diff --git a/.git-blame-ignore-revs b/.git-blame-ignore-revs
index 518de3672c..203d7b487a 100644
--- a/.git-blame-ignore-revs
+++ b/.git-blame-ignore-revs
@@ -69,3 +69,4 @@ cdf40d265cc82775607a1bf25f5f527bacc97405
 742cfa606039ab89602fde5fef46458516f56fd4
 4ad46f46de7dde753b4653c15f05326f55116b73
 75db098206b064b8b7b2a0604d3f0bf8fdb950cc
+84609494b54ea9732f64add43b2f1dd035632b4c
diff --git a/python/ctsm/longitude.py b/python/ctsm/longitude.py
index fb5998524d..96fd134082 100644
--- a/python/ctsm/longitude.py
+++ b/python/ctsm/longitude.py
@@ -177,6 +177,13 @@ def __ge__(self, other):
         self._check_lons_same_type(other)
         return self._lon >= other._lon
 
+    def __str__(self):
+        """
+        We don't allow implicit string conversion because the user should always specify the
+        Longitude type they want
+        """
+        raise NotImplementedError("Use Longitude.get_str() instead of implicit string conversion")
+
     def get(self, lon_type_out):
         """
         Get the longitude value, converting longitude type if needed
@@ -189,6 +196,14 @@ def get(self, lon_type_out):
             return _convert_lon_type_180_to_360(self._lon)
         raise RuntimeError(f"Add handling for lon_type_out {lon_type_out}")
 
+    def get_str(self, lon_type_out):
+        """
+        Get the longitude value as a string, converting longitude type if needed
+        """
+        lon_out = self.get(lon_type_out)
+        # Use float() because the standard in CTSM filenames is to put .0 after whole-number values
+        return str(float(lon_out))
+
     def lon_type(self):
         """
         Getter method for self._lon_type
diff --git a/python/ctsm/site_and_regional/regional_case.py b/python/ctsm/site_and_regional/regional_case.py
index ed91f3d474..1b52e72ab4 100644
--- a/python/ctsm/site_and_regional/regional_case.py
+++ b/python/ctsm/site_and_regional/regional_case.py
@@ -160,6 +160,20 @@ def _subset_lon_lat(self, x_dim, y_dim, f_in):
         f_out = f_in.isel({y_dim: yind, x_dim: xind})
         return f_out
 
+    def _get_lon_strings(self):
+        """
+        Get the string versions of the region's longitudes
+        """
+        if isinstance(self.lon1, Longitude):
+            lon1_str = self.lon1.get_str(self.lon1.lon_type())
+        else:
+            lon1_str = str(self.lon1)
+        if isinstance(self.lon2, Longitude):
+            lon2_str = self.lon2.get_str(self.lon2.lon_type())
+        else:
+            lon2_str = str(self.lon2)
+        return lon1_str, lon2_str
+
     def create_tag(self):
         """
         Create a tag for a region which is either the region name
@@ -169,9 +183,8 @@ def create_tag(self):
         if self.reg_name:
             self.tag = self.reg_name
         else:
-            self.tag = "{}-{}_{}-{}".format(
-                str(self.lon1), str(self.lon2), str(self.lat1), str(self.lat2)
-            )
+            lon1_str, lon2_str = self._get_lon_strings()
+            self.tag = "{}-{}_{}-{}".format(lon1_str, lon2_str, str(self.lat1), str(self.lat2))
 
     def check_region_bounds(self):
         """
@@ -179,10 +192,11 @@ def check_region_bounds(self):
         """
         # If you're calling this, lat/lon bounds need to have been provided
         if any(x is None for x in [self.lon1, self.lon2, self.lat1, self.lat2]):
+            lon1_str, lon2_str = self._get_lon_strings()
             raise argparse.ArgumentTypeError(
                 "Latitude and longitude bounds must be provided and not None.\n"
-                + f"   lon1: {self.lon1}\n"
-                + f"   lon2: {self.lon2}\n"
+                + f"   lon1: {lon1_str}\n"
+                + f"   lon2: {lon2_str}\n"
                 + f"   lat1: {self.lat1}\n"
                 + f"   lat2: {self.lat2}"
             )
diff --git a/python/ctsm/site_and_regional/single_point_case.py b/python/ctsm/site_and_regional/single_point_case.py
index d71d014f36..c99a240513 100644
--- a/python/ctsm/site_and_regional/single_point_case.py
+++ b/python/ctsm/site_and_regional/single_point_case.py
@@ -159,9 +159,12 @@ def convert_plon_to_filetype_if_needed(self, lon_da):
             plon_orig = plon_in.get(plon_type)
             plon_out = plon_in.get(f_lon_type)
             if plon_orig != plon_out:
-                print(
-                    f"Converted plon from type {plon_type} (value {plon_orig}) "
-                    f"to type {f_lon_type} (value {plon_out})"
+                logger.info(
+                    "Converted plon from type %s (value %f) to type %s (value %f)",
+                    plon_type,
+                    plon_orig,
+                    f_lon_type,
+                    plon_out,
                 )
         return plon_out
 
@@ -173,7 +176,7 @@ def create_tag(self):
         if self.site_name:
             self.tag = self.site_name
         else:
-            self.tag = "{}_{}".format(str(self.plon), str(self.plat))
+            self.tag = "{}_{}".format(self.plon.get_str(self.plon.lon_type()), str(self.plat))
 
     def check_dom_pft(self):
         """
@@ -333,7 +336,11 @@ def create_domain_at_point(self, indir, file):
         Create domain file for this SinglePointCase class.
         """
         logger.info("----------------------------------------------------------------------")
-        logger.info("Creating domain file at %s, %s.", str(self.plon), str(self.plat))
+        logger.info(
+            "Creating domain file at %s, %s.",
+            self.plon.get_str(self.plon.lon_type()),
+            str(self.plat),
+        )
 
         # specify files
         fdomain_in = os.path.join(indir, file)
@@ -367,7 +374,7 @@ def create_landuse_at_point(self, indir, file, user_mods_dir):
         logger.info("----------------------------------------------------------------------")
         logger.info(
             "Creating land use file at %s, %s.",
-            str(self.plon),
+            self.plon.get_str(self.plon.lon_type()),
             str(self.plat),
         )
 
@@ -502,7 +509,7 @@ def create_surfdata_at_point(self, indir, file, user_mods_dir, specify_fsurf_out
         logger.info("----------------------------------------------------------------------")
         logger.info(
             "Creating surface dataset file at %s, %s",
-            str(self.plon),
+            self.plon.get_str(self.plon.lon_type()),
             str(self.plat),
         )
 
@@ -577,7 +584,7 @@ def create_datmdomain_at_point(self, datm_tuple: DatmFiles):
         logger.info("----------------------------------------------------------------------")
         logger.info(
             "Creating DATM domain file at %s, %s",
-            str(self.plon),
+            self.plon.get_str(self.plon.lon_type()),
             str(self.plat),
         )
 
@@ -646,7 +653,9 @@ def write_shell_commands(self, file, datm_syr, datm_eyr):
         with open(file, "w") as nl_file:
             self.write_to_file("# Change below line if you move the subset data directory", nl_file)
             self.write_to_file("./xmlchange {}={}".format(USRDAT_DIR, self.out_dir), nl_file)
-            self.write_to_file("./xmlchange PTS_LON={}".format(str(self.plon)), nl_file)
+            self.write_to_file(
+                "./xmlchange PTS_LON={}".format(self.plon.get_str(self.plon.lon_type())), nl_file
+            )
             self.write_to_file("./xmlchange PTS_LAT={}".format(str(self.plat)), nl_file)
             self.write_to_file("./xmlchange MPILIB=mpi-serial", nl_file)
             if self.create_datm:
@@ -672,7 +681,9 @@ def create_datm_at_point(self, datm_tuple: DatmFiles, datm_syr, datm_eyr, datm_s
         Create all of a DATM dataset at a point.
         """
         logger.info("----------------------------------------------------------------------")
-        logger.info("Creating DATM files at %s, %s", str(self.plon), str(self.plat))
+        logger.info(
+            "Creating DATM files at %s, %s", self.plon.get_str(self.plon.lon_type()), str(self.plat)
+        )
 
         # --  create data files
         infile = []
diff --git a/python/ctsm/subset_data.py b/python/ctsm/subset_data.py
index 1fe7f8c580..ed9282ef46 100644
--- a/python/ctsm/subset_data.py
+++ b/python/ctsm/subset_data.py
@@ -822,7 +822,7 @@ def subset_region(args, file_dict: dict):
         print("\nFor running this regional case with the created user_mods : ")
         print(
             "./create_newcase --case case --res CLM_USRDAT --compset I2000Clm60BgcCrop",
-            "--run-unsupported --user-mods-dirs ",
+            "--run-unsupported --user-mods-dir ",
             args.user_mods_dir,
             "\n\n",
         )
diff --git a/python/ctsm/test/test_sys_subset_data.py b/python/ctsm/test/test_sys_subset_data.py
index 39d448cccd..453df7c18e 100644
--- a/python/ctsm/test/test_sys_subset_data.py
+++ b/python/ctsm/test/test_sys_subset_data.py
@@ -12,6 +12,7 @@
 import tempfile
 import inspect
 import xarray as xr
+from CIME.scripts.create_newcase import _main_func as create_newcase  # pylint: disable=import-error
 
 # -- add python/ctsm  to path (needed if we want to run the test stand-alone)
 _CTSM_PYTHON = os.path.join(os.path.dirname(os.path.realpath(__file__)), os.pardir, os.pardir)
@@ -23,19 +24,52 @@
 from ctsm.utils import find_one_file_matching_pattern
 
 
+def _get_sitename_str_point(include_sitename, sitename, lon, lat):
+    """
+    Given a site, return the string to use in output filenames
+    """
+    if include_sitename:
+        sitename_str = sitename
+    else:
+        sitename_str = f"{float(lon)}_{float(lat)}"
+    return sitename_str
+
+
 class TestSubsetDataSys(unittest.TestCase):
     """
     Basic class for testing subset_data.py.
     """
 
     def setUp(self):
+        self.previous_dir = os.getcwd()
         self.temp_dir_out = tempfile.TemporaryDirectory()
         self.temp_dir_umd = tempfile.TemporaryDirectory()
+        self.temp_dir_caseparent = tempfile.TemporaryDirectory()
         self.inputdata_dir = os.path.join(os.path.dirname(__file__), os.pardir, os.pardir)
 
     def tearDown(self):
         self.temp_dir_out.cleanup()
         self.temp_dir_umd.cleanup()
+        os.chdir(self.previous_dir)
+
+    def _check_create_newcase(self):
+        """
+        Check that you can call create_newcase using the usermods from subset_data
+        """
+        case_dir = os.path.join(self.temp_dir_caseparent.name, "case")
+        sys.argv = [
+            "create_newcase",
+            "--case",
+            case_dir,
+            "--res",
+            "CLM_USRDAT",
+            "--compset",
+            "I2000Clm60Bgc",
+            "--run-unsupported",
+            "--user-mods-dir",
+            self.temp_dir_umd.name,
+        ]
+        create_newcase()
 
     def _check_result_file_matches_expected(self, expected_output_files, caller_n):
         """
@@ -46,9 +80,18 @@ def _check_result_file_matches_expected(self, expected_output_files, caller_n):
         caller_n = 1. If the test is calling a function that calls this function, caller_n = 2. Etc.
         """
         all_files_present_and_match = True
+        result_file_found = True
+        expected_file_found = True
         for basename in expected_output_files:
+
+            # Check whether result (output) file exists. If not, note it but continue.
             result_file = os.path.join(self.temp_dir_out.name, basename)
-            result_file = find_one_file_matching_pattern(result_file)
+            try:
+                result_file = find_one_file_matching_pattern(result_file)
+            except FileNotFoundError:
+                result_file_found = False
+
+            # Check whether expected file exists. If not, note it but continue.
             expected_file = os.path.join(
                 os.path.dirname(__file__),
                 "testinputs",
@@ -56,7 +99,27 @@ def _check_result_file_matches_expected(self, expected_output_files, caller_n):
                 inspect.stack()[caller_n][3],  # Name of calling function (i.e., test name)
                 basename,
             )
-            expected_file = find_one_file_matching_pattern(expected_file)
+            try:
+                expected_file = find_one_file_matching_pattern(expected_file)
+            except FileNotFoundError:
+                expected_file_found = False
+
+            # Raise an AssertionError if either file was not found
+            if not (result_file_found and expected_file_found):
+                msg = ""
+                if not result_file_found:
+                    this_dir = os.path.dirname(result_file)
+                    msg += f"\nResult file '{result_file}' not found. "
+                    msg += f"Contents of directory '{this_dir}':\n\t"
+                    msg += "\n\t".join(os.listdir(this_dir))
+                if not expected_file_found:
+                    this_dir = os.path.dirname(expected_file)
+                    msg += f"\nExpected file '{expected_file}' not found. "
+                    msg += f"Contents of directory '{this_dir}':\n\t"
+                    msg += "\n\t".join(os.listdir(this_dir))
+                raise AssertionError(msg)
+
+            # Compare the two files
             ds_result = xr.open_dataset(result_file)
             ds_expected = xr.open_dataset(expected_file)
             if not ds_result.equals(ds_expected):
@@ -66,10 +129,15 @@ def _check_result_file_matches_expected(self, expected_output_files, caller_n):
                 all_files_present_and_match = False
         return all_files_present_and_match
 
-    def test_subset_data_reg_amazon(self):
+    def _do_test_subset_data_reg_amazon(self, include_regname=True):
         """
-        Test subset_data for Amazon region
+        Convenience function for multiple tests of subset_data region for the Amazon
         """
+        regname = "TMP"
+        lat1 = -12
+        lat2 = -7
+        lon1 = 291
+        lon2 = 299
         cfg_file = os.path.join(
             self.inputdata_dir,
             "ctsm",
@@ -82,15 +150,13 @@ def test_subset_data_reg_amazon(self):
             "subset_data",
             "region",
             "--lat1",
-            "-12",
+            str(lat1),
             "--lat2",
-            "-7",
+            str(lat2),
             "--lon1",
-            "291",
+            str(lon1),
             "--lon2",
-            "299",
-            "--reg",
-            "TMP",
+            str(lon2),
             "--create-mesh",
             "--create-domain",
             "--create-surface",
@@ -107,16 +173,40 @@ def test_subset_data_reg_amazon(self):
             cfg_file,
             "--overwrite",
         ]
+        if include_regname:
+            sys.argv += ["--reg", regname]
         subset_data.main()
 
         # Loop through all the output files, making sure they match what we expect.
         daystr = "[0-9][0-9][0-9][0-9][0-9][0-9]"  # 6-digit day code, yymmdd
+        if include_regname:
+            regname_str = regname
+        else:
+            regname_str = f"{float(lon1)}-{float(lon2)}_{float(lat1)}-{float(lat2)}"
         expected_output_files = [
-            f"domain.lnd.5x5pt-amazon_navy_TMP_c{daystr}_ESMF_UNSTRUCTURED_MESH.nc",
-            f"domain.lnd.5x5pt-amazon_navy_TMP_c{daystr}.nc",
-            f"surfdata_TMP_amazon_hist_16pfts_CMIP6_2000_c{daystr}.nc",
+            f"domain.lnd.5x5pt-amazon_navy_{regname_str}_c{daystr}_ESMF_UNSTRUCTURED_MESH.nc",
+            f"domain.lnd.5x5pt-amazon_navy_{regname_str}_c{daystr}.nc",
+            f"surfdata_{regname_str}_amazon_hist_16pfts_CMIP6_2000_c{daystr}.nc",
         ]
-        self.assertTrue(self._check_result_file_matches_expected(expected_output_files, 1))
+        self.assertTrue(self._check_result_file_matches_expected(expected_output_files, 2))
+
+        # Check that create_newcase works
+        # SHOULD WORK ONLY ON CESM-SUPPORTED MACHINES
+        self._check_create_newcase()
+
+    def test_subset_data_reg_amazon(self):
+        """
+        Test subset_data for Amazon region
+        SHOULD WORK ONLY ON CESM-SUPPORTED MACHINES
+        """
+        self._do_test_subset_data_reg_amazon()
+
+    def test_subset_data_reg_amazon_noregname(self):
+        """
+        Test subset_data for Amazon region
+        SHOULD WORK ONLY ON CESM-SUPPORTED MACHINES
+        """
+        self._do_test_subset_data_reg_amazon(include_regname=False)
 
     def test_subset_data_reg_infile_detect360(self):
         """
@@ -189,10 +279,11 @@ def test_subset_data_reg_infile_detect180_error(self):
         ):
             subset_data.main()
 
-    def _do_test_subset_data_pt_surface(self, lon):
+    def _do_test_subset_data_pt_surface(self, lon, include_sitename=True):
         """
         Given a longitude, test subset_data point --create-surface
         """
+        lat = -12
         cfg_file = os.path.join(
             self.inputdata_dir,
             "ctsm",
@@ -205,11 +296,9 @@ def _do_test_subset_data_pt_surface(self, lon):
             "subset_data",
             "point",
             "--lat",
-            "-12",
+            str(lat),
             "--lon",
             str(lon),
-            "--site",
-            "TMP",
             "--create-domain",
             "--create-surface",
             "--surf-year",
@@ -225,31 +314,51 @@ def _do_test_subset_data_pt_surface(self, lon):
             cfg_file,
             "--overwrite",
         ]
+        sitename = "TMP"
+        if include_sitename:
+            sys.argv += ["--site", sitename]
         subset_data.main()
 
         # Loop through all the output files, making sure they match what we expect.
         daystr = "[0-9][0-9][0-9][0-9][0-9][0-9]"  # 6-digit day code, yymmdd
+        sitename_str = _get_sitename_str_point(include_sitename, sitename, lon, lat)
         expected_output_files = [
-            f"surfdata_TMP_amazon_hist_16pfts_CMIP6_2000_c{daystr}.nc",
+            f"surfdata_{sitename_str}_amazon_hist_16pfts_CMIP6_2000_c{daystr}.nc",
         ]
         self.assertTrue(self._check_result_file_matches_expected(expected_output_files, 2))
 
+        # Check that create_newcase works
+        # SHOULD WORK ONLY ON CESM-SUPPORTED MACHINES
+        self._check_create_newcase()
+
     def test_subset_data_pt_surface_amazon_type360(self):
         """
         Test subset_data --create-surface for Amazon point with longitude type 360
+        SHOULD WORK ONLY ON CESM-SUPPORTED MACHINES
         """
         self._do_test_subset_data_pt_surface(291)
 
     def test_subset_data_pt_surface_amazon_type180(self):
         """
         Test subset_data --create-surface for Amazon point with longitude type 180
+        SHOULD WORK ONLY ON CESM-SUPPORTED MACHINES
         """
         self._do_test_subset_data_pt_surface(-69)
 
-    def _do_test_subset_data_pt_landuse(self, lon):
+    def test_subset_data_pt_surface_amazon_type180_nositename(self):
+        """
+        Test subset_data --create-surface for Amazon point with longitude type 180
+        without specifying a site name
+        SHOULD WORK ONLY ON CESM-SUPPORTED MACHINES
+        """
+        self._do_test_subset_data_pt_surface(-69, include_sitename=False)
+
+    def _do_test_subset_data_pt_landuse(self, lon, include_sitename=True):
         """
         Given a longitude, test subset_data point --create-landuse
         """
+        lat = -12
+        sitename = "TMP"
         cfg_file = os.path.join(
             self.inputdata_dir,
             "ctsm",
@@ -262,11 +371,9 @@ def _do_test_subset_data_pt_landuse(self, lon):
             "subset_data",
             "point",
             "--lat",
-            "-12",
+            str(lat),
             "--lon",
             str(lon),
-            "--site",
-            "TMP",
             "--create-domain",
             "--create-surface",
             "--surf-year",
@@ -283,45 +390,60 @@ def _do_test_subset_data_pt_landuse(self, lon):
             cfg_file,
             "--overwrite",
         ]
+        if include_sitename:
+            sys.argv += ["--site", sitename]
         subset_data.main()
 
         # Loop through all the output files, making sure they match what we expect.
         daystr = "[0-9][0-9][0-9][0-9][0-9][0-9]"  # 6-digit day code, yymmdd
+        sitename_str = _get_sitename_str_point(include_sitename, sitename, lon, lat)
         expected_output_files = [
-            f"surfdata_TMP_amazon_hist_1850_78pfts_c{daystr}.nc",
-            f"landuse.timeseries_TMP_amazon_hist_1850-1853_78pfts_c{daystr}.nc",
+            f"surfdata_{sitename_str}_amazon_hist_1850_78pfts_c{daystr}.nc",
+            f"landuse.timeseries_{sitename_str}_amazon_hist_1850-1853_78pfts_c{daystr}.nc",
         ]
         self.assertTrue(self._check_result_file_matches_expected(expected_output_files, 2))
 
+        # Check that create_newcase works
+        # SHOULD WORK ONLY ON CESM-SUPPORTED MACHINES
+        self._check_create_newcase()
+
     def test_subset_data_pt_landuse_amazon_type360(self):
         """
         Test subset_data --create-landuse for Amazon point with longitude type 360
+        SHOULD WORK ONLY ON CESM-SUPPORTED MACHINES
         """
         self._do_test_subset_data_pt_landuse(291)
 
+    def test_subset_data_pt_landuse_amazon_type360_nositename(self):
+        """
+        Test subset_data --create-landuse for Amazon point with longitude type 360 and no site name
+        SHOULD WORK ONLY ON CESM-SUPPORTED MACHINES
+        """
+        self._do_test_subset_data_pt_landuse(291, include_sitename=False)
+
     def test_subset_data_pt_landuse_amazon_type180(self):
         """
         Test subset_data --create-landuse for Amazon point with longitude type 180
+        SHOULD WORK ONLY ON CESM-SUPPORTED MACHINES
         """
         self._do_test_subset_data_pt_landuse(-69)
 
-    def _do_test_subset_data_pt_datm(self, lon):
+    def _do_test_subset_data_pt_datm(self, lon, include_sitename=True):
         """
         Given a longitude, test subset_data point --create-datm
         """
         start_year = 1986
         end_year = 1988
         sitename = "TMP"
+        lat = -12
         outdir = self.temp_dir_out.name
         sys.argv = [
             "subset_data",
             "point",
             "--lat",
-            "-12",
+            str(lat),
             "--lon",
             str(lon),
-            "--site",
-            sitename,
             "--create-datm",
             "--datm-syr",
             str(start_year),
@@ -334,21 +456,27 @@ def _do_test_subset_data_pt_datm(self, lon):
             self.temp_dir_umd.name,
             "--overwrite",
         ]
+        if include_sitename:
+            sys.argv += ["--site", sitename]
         subset_data.main()
 
         # Loop through all the output files, making sure they match what we expect.
         daystr = "[0-9][0-9][0-9][0-9][0-9][0-9]"  # 6-digit day code, yymmdd
+        sitename_str = _get_sitename_str_point(include_sitename, sitename, lon, lat)
         expected_output_files = [
-            f"domain.crujra_v2.3_0.5x0.5_{sitename}_c{daystr}.nc",
+            f"domain.crujra_v2.3_0.5x0.5_{sitename_str}_c{daystr}.nc",
         ]
         for year in list(range(start_year, end_year + 1)):
             for forcing in ["Solr", "Prec", "TPQWL"]:
                 expected_output_files.append(
-                    f"clmforc.CRUJRAv2.5_0.5x0.5.{forcing}.{sitename}.{year}.nc"
+                    f"clmforc.CRUJRAv2.5_0.5x0.5.{forcing}.{sitename_str}.{year}.nc"
                 )
         expected_output_files = [os.path.join("datmdata", x) for x in expected_output_files]
         self.assertTrue(self._check_result_file_matches_expected(expected_output_files, 2))
 
+        # Check that create_newcase works
+        self._check_create_newcase()
+
     def test_subset_data_pt_datm_amazon_type360(self):
         """
         Test subset_data --create-datm for Amazon point with longitude type 360
@@ -363,6 +491,14 @@ def test_subset_data_pt_datm_amazon_type180(self):
         """
         self._do_test_subset_data_pt_datm(-69)
 
+    def test_subset_data_pt_datm_amazon_type180_nositename(self):
+        """
+        Test subset_data --create-datm for Amazon point with longitude type 180 without providing
+        site name.
+        FOR NOW CAN ONLY BE RUN ON DERECHO/CASPER
+        """
+        self._do_test_subset_data_pt_datm(-69, include_sitename=False)
+
 
 if __name__ == "__main__":
     unit_testing.setup_for_tests()
diff --git a/python/ctsm/test/test_unit_longitude.py b/python/ctsm/test/test_unit_longitude.py
index 6766f90764..2382b2c303 100644
--- a/python/ctsm/test/test_unit_longitude.py
+++ b/python/ctsm/test/test_unit_longitude.py
@@ -446,6 +446,27 @@ def test_lon_type_getter(self):
         lon = Longitude(55, 180)
         self.assertEqual(lon.lon_type(), 180)
 
+    def test_no_implicit_string_conversion(self):
+        """Ensure that implicit string conversion is disallowed"""
+        lon = Longitude(55, 180)
+        with self.assertRaisesRegex(
+            NotImplementedError, r"Use Longitude\.get_str\(\) instead of implicit string conversion"
+        ):
+            _ = f"{lon}"
+        with self.assertRaisesRegex(
+            NotImplementedError, r"Use Longitude\.get_str\(\) instead of implicit string conversion"
+        ):
+            _ = str(lon)
+
+    def test_get_str(self):
+        """Ensure that explicit string conversion works as expected"""
+        lon = Longitude(55, 180)
+        self.assertEqual(lon.get_str(180), "55.0")
+        self.assertEqual(lon.get_str(360), "55.0")
+        lon = Longitude(-55, 180)
+        self.assertEqual(lon.get_str(180), "-55.0")
+        self.assertEqual(lon.get_str(360), "305.0")
+
 
 if __name__ == "__main__":
     unit_testing.setup_for_tests()
diff --git a/python/ctsm/test/test_unit_singlept_data.py b/python/ctsm/test/test_unit_singlept_data.py
index bf29ced331..489763282d 100755
--- a/python/ctsm/test/test_unit_singlept_data.py
+++ b/python/ctsm/test/test_unit_singlept_data.py
@@ -19,6 +19,7 @@
 from ctsm import unit_testing
 from ctsm.site_and_regional.single_point_case import SinglePointCase
 from ctsm.pft_utils import MAX_PFT_GENERICCROPS, MAX_PFT_MANAGEDCROPS
+from ctsm.longitude import Longitude
 
 # pylint: disable=invalid-name
 
@@ -29,7 +30,7 @@ class TestSinglePointCase(unittest.TestCase):
     """
 
     plat = 20.1
-    plon = 50.5
+    plon = Longitude(50.5, lon_type=180)
     site_name = None
     create_domain = True
     create_surfdata = True
diff --git a/python/ctsm/test/test_unit_singlept_data_surfdata.py b/python/ctsm/test/test_unit_singlept_data_surfdata.py
index d163c29e4f..11ee416d4a 100755
--- a/python/ctsm/test/test_unit_singlept_data_surfdata.py
+++ b/python/ctsm/test/test_unit_singlept_data_surfdata.py
@@ -24,6 +24,7 @@
 from ctsm import unit_testing
 from ctsm.site_and_regional.single_point_case import SinglePointCase
 from ctsm.pft_utils import MAX_PFT_GENERICCROPS, MAX_PFT_MANAGEDCROPS
+from ctsm.longitude import Longitude
 
 # pylint: disable=invalid-name
 # pylint: disable=too-many-lines
@@ -37,7 +38,7 @@ class TestSinglePointCaseSurfaceNoCrop(unittest.TestCase):
     """
 
     plat = 20.1
-    plon = 50.5
+    plon = Longitude(50.5, lon_type=180)
     site_name = None
     create_domain = True
     create_surfdata = True
@@ -658,7 +659,7 @@ class TestSinglePointCaseSurfaceCrop(unittest.TestCase):
     """
 
     plat = 20.1
-    plon = 50.5
+    plon = Longitude(50.5, lon_type=180)
     site_name = None
     create_domain = True
     create_surfdata = True
diff --git a/python/ctsm/test/testinputs/expected_result_files/test_subset_data_pt_datm_amazon_type180_nositename/datmdata/clmforc.CRUJRAv2.5_0.5x0.5.Prec.-69.0_-12.0.1986.nc b/python/ctsm/test/testinputs/expected_result_files/test_subset_data_pt_datm_amazon_type180_nositename/datmdata/clmforc.CRUJRAv2.5_0.5x0.5.Prec.-69.0_-12.0.1986.nc
new file mode 120000
index 0000000000..0e14bd986a
--- /dev/null
+++ b/python/ctsm/test/testinputs/expected_result_files/test_subset_data_pt_datm_amazon_type180_nositename/datmdata/clmforc.CRUJRAv2.5_0.5x0.5.Prec.-69.0_-12.0.1986.nc
@@ -0,0 +1 @@
+../../test_subset_data_pt_datm_amazon_type180/datmdata//clmforc.CRUJRAv2.5_0.5x0.5.Prec.TMP.1986.nc
\ No newline at end of file
diff --git a/python/ctsm/test/testinputs/expected_result_files/test_subset_data_pt_datm_amazon_type180_nositename/datmdata/clmforc.CRUJRAv2.5_0.5x0.5.Prec.-69.0_-12.0.1987.nc b/python/ctsm/test/testinputs/expected_result_files/test_subset_data_pt_datm_amazon_type180_nositename/datmdata/clmforc.CRUJRAv2.5_0.5x0.5.Prec.-69.0_-12.0.1987.nc
new file mode 120000
index 0000000000..28b7abf80d
--- /dev/null
+++ b/python/ctsm/test/testinputs/expected_result_files/test_subset_data_pt_datm_amazon_type180_nositename/datmdata/clmforc.CRUJRAv2.5_0.5x0.5.Prec.-69.0_-12.0.1987.nc
@@ -0,0 +1 @@
+../../test_subset_data_pt_datm_amazon_type180/datmdata//clmforc.CRUJRAv2.5_0.5x0.5.Prec.TMP.1987.nc
\ No newline at end of file
diff --git a/python/ctsm/test/testinputs/expected_result_files/test_subset_data_pt_datm_amazon_type180_nositename/datmdata/clmforc.CRUJRAv2.5_0.5x0.5.Prec.-69.0_-12.0.1988.nc b/python/ctsm/test/testinputs/expected_result_files/test_subset_data_pt_datm_amazon_type180_nositename/datmdata/clmforc.CRUJRAv2.5_0.5x0.5.Prec.-69.0_-12.0.1988.nc
new file mode 120000
index 0000000000..a238ab07c2
--- /dev/null
+++ b/python/ctsm/test/testinputs/expected_result_files/test_subset_data_pt_datm_amazon_type180_nositename/datmdata/clmforc.CRUJRAv2.5_0.5x0.5.Prec.-69.0_-12.0.1988.nc
@@ -0,0 +1 @@
+../../test_subset_data_pt_datm_amazon_type180/datmdata//clmforc.CRUJRAv2.5_0.5x0.5.Prec.TMP.1988.nc
\ No newline at end of file
diff --git a/python/ctsm/test/testinputs/expected_result_files/test_subset_data_pt_datm_amazon_type180_nositename/datmdata/clmforc.CRUJRAv2.5_0.5x0.5.Solr.-69.0_-12.0.1986.nc b/python/ctsm/test/testinputs/expected_result_files/test_subset_data_pt_datm_amazon_type180_nositename/datmdata/clmforc.CRUJRAv2.5_0.5x0.5.Solr.-69.0_-12.0.1986.nc
new file mode 120000
index 0000000000..a2045e914c
--- /dev/null
+++ b/python/ctsm/test/testinputs/expected_result_files/test_subset_data_pt_datm_amazon_type180_nositename/datmdata/clmforc.CRUJRAv2.5_0.5x0.5.Solr.-69.0_-12.0.1986.nc
@@ -0,0 +1 @@
+../../test_subset_data_pt_datm_amazon_type180/datmdata//clmforc.CRUJRAv2.5_0.5x0.5.Solr.TMP.1986.nc
\ No newline at end of file
diff --git a/python/ctsm/test/testinputs/expected_result_files/test_subset_data_pt_datm_amazon_type180_nositename/datmdata/clmforc.CRUJRAv2.5_0.5x0.5.Solr.-69.0_-12.0.1987.nc b/python/ctsm/test/testinputs/expected_result_files/test_subset_data_pt_datm_amazon_type180_nositename/datmdata/clmforc.CRUJRAv2.5_0.5x0.5.Solr.-69.0_-12.0.1987.nc
new file mode 120000
index 0000000000..24cc171353
--- /dev/null
+++ b/python/ctsm/test/testinputs/expected_result_files/test_subset_data_pt_datm_amazon_type180_nositename/datmdata/clmforc.CRUJRAv2.5_0.5x0.5.Solr.-69.0_-12.0.1987.nc
@@ -0,0 +1 @@
+../../test_subset_data_pt_datm_amazon_type180/datmdata//clmforc.CRUJRAv2.5_0.5x0.5.Solr.TMP.1987.nc
\ No newline at end of file
diff --git a/python/ctsm/test/testinputs/expected_result_files/test_subset_data_pt_datm_amazon_type180_nositename/datmdata/clmforc.CRUJRAv2.5_0.5x0.5.Solr.-69.0_-12.0.1988.nc b/python/ctsm/test/testinputs/expected_result_files/test_subset_data_pt_datm_amazon_type180_nositename/datmdata/clmforc.CRUJRAv2.5_0.5x0.5.Solr.-69.0_-12.0.1988.nc
new file mode 120000
index 0000000000..00eacece43
--- /dev/null
+++ b/python/ctsm/test/testinputs/expected_result_files/test_subset_data_pt_datm_amazon_type180_nositename/datmdata/clmforc.CRUJRAv2.5_0.5x0.5.Solr.-69.0_-12.0.1988.nc
@@ -0,0 +1 @@
+../../test_subset_data_pt_datm_amazon_type180/datmdata//clmforc.CRUJRAv2.5_0.5x0.5.Solr.TMP.1988.nc
\ No newline at end of file
diff --git a/python/ctsm/test/testinputs/expected_result_files/test_subset_data_pt_datm_amazon_type180_nositename/datmdata/clmforc.CRUJRAv2.5_0.5x0.5.TPQWL.-69.0_-12.0.1986.nc b/python/ctsm/test/testinputs/expected_result_files/test_subset_data_pt_datm_amazon_type180_nositename/datmdata/clmforc.CRUJRAv2.5_0.5x0.5.TPQWL.-69.0_-12.0.1986.nc
new file mode 120000
index 0000000000..3806e36151
--- /dev/null
+++ b/python/ctsm/test/testinputs/expected_result_files/test_subset_data_pt_datm_amazon_type180_nositename/datmdata/clmforc.CRUJRAv2.5_0.5x0.5.TPQWL.-69.0_-12.0.1986.nc
@@ -0,0 +1 @@
+../../test_subset_data_pt_datm_amazon_type180/datmdata//clmforc.CRUJRAv2.5_0.5x0.5.TPQWL.TMP.1986.nc
\ No newline at end of file
diff --git a/python/ctsm/test/testinputs/expected_result_files/test_subset_data_pt_datm_amazon_type180_nositename/datmdata/clmforc.CRUJRAv2.5_0.5x0.5.TPQWL.-69.0_-12.0.1987.nc b/python/ctsm/test/testinputs/expected_result_files/test_subset_data_pt_datm_amazon_type180_nositename/datmdata/clmforc.CRUJRAv2.5_0.5x0.5.TPQWL.-69.0_-12.0.1987.nc
new file mode 120000
index 0000000000..44ce035a2a
--- /dev/null
+++ b/python/ctsm/test/testinputs/expected_result_files/test_subset_data_pt_datm_amazon_type180_nositename/datmdata/clmforc.CRUJRAv2.5_0.5x0.5.TPQWL.-69.0_-12.0.1987.nc
@@ -0,0 +1 @@
+../../test_subset_data_pt_datm_amazon_type180/datmdata//clmforc.CRUJRAv2.5_0.5x0.5.TPQWL.TMP.1987.nc
\ No newline at end of file
diff --git a/python/ctsm/test/testinputs/expected_result_files/test_subset_data_pt_datm_amazon_type180_nositename/datmdata/clmforc.CRUJRAv2.5_0.5x0.5.TPQWL.-69.0_-12.0.1988.nc b/python/ctsm/test/testinputs/expected_result_files/test_subset_data_pt_datm_amazon_type180_nositename/datmdata/clmforc.CRUJRAv2.5_0.5x0.5.TPQWL.-69.0_-12.0.1988.nc
new file mode 120000
index 0000000000..cd8cdfb7c9
--- /dev/null
+++ b/python/ctsm/test/testinputs/expected_result_files/test_subset_data_pt_datm_amazon_type180_nositename/datmdata/clmforc.CRUJRAv2.5_0.5x0.5.TPQWL.-69.0_-12.0.1988.nc
@@ -0,0 +1 @@
+../../test_subset_data_pt_datm_amazon_type180/datmdata//clmforc.CRUJRAv2.5_0.5x0.5.TPQWL.TMP.1988.nc
\ No newline at end of file
diff --git a/python/ctsm/test/testinputs/expected_result_files/test_subset_data_pt_datm_amazon_type180_nositename/datmdata/domain.crujra_v2.3_0.5x0.5_-69.0_-12.0_c250620.nc b/python/ctsm/test/testinputs/expected_result_files/test_subset_data_pt_datm_amazon_type180_nositename/datmdata/domain.crujra_v2.3_0.5x0.5_-69.0_-12.0_c250620.nc
new file mode 120000
index 0000000000..1dc0d0d5f2
--- /dev/null
+++ b/python/ctsm/test/testinputs/expected_result_files/test_subset_data_pt_datm_amazon_type180_nositename/datmdata/domain.crujra_v2.3_0.5x0.5_-69.0_-12.0_c250620.nc
@@ -0,0 +1 @@
+../../test_subset_data_pt_datm_amazon_type180/datmdata//domain.crujra_v2.3_0.5x0.5_TMP_c250620.nc
\ No newline at end of file
diff --git a/python/ctsm/test/testinputs/expected_result_files/test_subset_data_pt_landuse_amazon_type360_nositename/landuse.timeseries_291.0_-12.0_amazon_hist_1850-1853_78pfts_c250618.nc b/python/ctsm/test/testinputs/expected_result_files/test_subset_data_pt_landuse_amazon_type360_nositename/landuse.timeseries_291.0_-12.0_amazon_hist_1850-1853_78pfts_c250618.nc
new file mode 120000
index 0000000000..8678639d98
--- /dev/null
+++ b/python/ctsm/test/testinputs/expected_result_files/test_subset_data_pt_landuse_amazon_type360_nositename/landuse.timeseries_291.0_-12.0_amazon_hist_1850-1853_78pfts_c250618.nc
@@ -0,0 +1 @@
+../test_subset_data_pt_landuse_amazon_type360/landuse.timeseries_TMP_amazon_hist_1850-1853_78pfts_c250618.nc
\ No newline at end of file
diff --git a/python/ctsm/test/testinputs/expected_result_files/test_subset_data_pt_landuse_amazon_type360_nositename/surfdata_291.0_-12.0_amazon_hist_1850_78pfts_c250618.nc b/python/ctsm/test/testinputs/expected_result_files/test_subset_data_pt_landuse_amazon_type360_nositename/surfdata_291.0_-12.0_amazon_hist_1850_78pfts_c250618.nc
new file mode 120000
index 0000000000..2efbb745f4
--- /dev/null
+++ b/python/ctsm/test/testinputs/expected_result_files/test_subset_data_pt_landuse_amazon_type360_nositename/surfdata_291.0_-12.0_amazon_hist_1850_78pfts_c250618.nc
@@ -0,0 +1 @@
+../test_subset_data_pt_landuse_amazon_type360/surfdata_TMP_amazon_hist_1850_78pfts_c250618.nc
\ No newline at end of file
diff --git a/python/ctsm/test/testinputs/expected_result_files/test_subset_data_pt_surface_amazon_type180_nositename/surfdata_-69.0_-12.0_amazon_hist_16pfts_CMIP6_2000_c250617.nc b/python/ctsm/test/testinputs/expected_result_files/test_subset_data_pt_surface_amazon_type180_nositename/surfdata_-69.0_-12.0_amazon_hist_16pfts_CMIP6_2000_c250617.nc
new file mode 120000
index 0000000000..9e811ca9c3
--- /dev/null
+++ b/python/ctsm/test/testinputs/expected_result_files/test_subset_data_pt_surface_amazon_type180_nositename/surfdata_-69.0_-12.0_amazon_hist_16pfts_CMIP6_2000_c250617.nc
@@ -0,0 +1 @@
+../test_subset_data_pt_surface_amazon_type180/surfdata_TMP_amazon_hist_16pfts_CMIP6_2000_c250617.nc
\ No newline at end of file
diff --git a/python/ctsm/test/testinputs/expected_result_files/test_subset_data_reg_amazon_noregname/domain.lnd.5x5pt-amazon_navy_291.0-299.0_-12.0--7.0_c250508.nc b/python/ctsm/test/testinputs/expected_result_files/test_subset_data_reg_amazon_noregname/domain.lnd.5x5pt-amazon_navy_291.0-299.0_-12.0--7.0_c250508.nc
new file mode 120000
index 0000000000..99d8401b46
--- /dev/null
+++ b/python/ctsm/test/testinputs/expected_result_files/test_subset_data_reg_amazon_noregname/domain.lnd.5x5pt-amazon_navy_291.0-299.0_-12.0--7.0_c250508.nc
@@ -0,0 +1 @@
+../test_subset_data_reg_amazon/domain.lnd.5x5pt-amazon_navy_TMP_c250508.nc
\ No newline at end of file
diff --git a/python/ctsm/test/testinputs/expected_result_files/test_subset_data_reg_amazon_noregname/domain.lnd.5x5pt-amazon_navy_291.0-299.0_-12.0--7.0_c250508_ESMF_UNSTRUCTURED_MESH.nc b/python/ctsm/test/testinputs/expected_result_files/test_subset_data_reg_amazon_noregname/domain.lnd.5x5pt-amazon_navy_291.0-299.0_-12.0--7.0_c250508_ESMF_UNSTRUCTURED_MESH.nc
new file mode 120000
index 0000000000..6f8ca4e665
--- /dev/null
+++ b/python/ctsm/test/testinputs/expected_result_files/test_subset_data_reg_amazon_noregname/domain.lnd.5x5pt-amazon_navy_291.0-299.0_-12.0--7.0_c250508_ESMF_UNSTRUCTURED_MESH.nc
@@ -0,0 +1 @@
+../test_subset_data_reg_amazon/domain.lnd.5x5pt-amazon_navy_TMP_c250508_ESMF_UNSTRUCTURED_MESH.nc
\ No newline at end of file
diff --git a/python/ctsm/test/testinputs/expected_result_files/test_subset_data_reg_amazon_noregname/surfdata_291.0-299.0_-12.0--7.0_amazon_hist_16pfts_CMIP6_2000_c250508.nc b/python/ctsm/test/testinputs/expected_result_files/test_subset_data_reg_amazon_noregname/surfdata_291.0-299.0_-12.0--7.0_amazon_hist_16pfts_CMIP6_2000_c250508.nc
new file mode 120000
index 0000000000..73bde404b0
--- /dev/null
+++ b/python/ctsm/test/testinputs/expected_result_files/test_subset_data_reg_amazon_noregname/surfdata_291.0-299.0_-12.0--7.0_amazon_hist_16pfts_CMIP6_2000_c250508.nc
@@ -0,0 +1 @@
+../test_subset_data_reg_amazon/surfdata_TMP_amazon_hist_16pfts_CMIP6_2000_c250508.nc
\ No newline at end of file