swiss-weather-mcp

swiss-weather-mcp is a JSON-RPC 2.0 MCP server over stdio that exposes Swiss weather, pollen, radiation, UV, and air-quality data.

The server reads one JSON-RPC request per line from stdin and writes one JSON-RPC response per line to stdout.

Install

Install from crates.io:

cargo install swiss-weather-mcp

Configure In An MCP Client

swiss-weather-mcp is a stdio MCP server. There is no separate config file, no required environment variables, and no command-line arguments to set up. Configure your MCP client to launch the installed binary directly.

Example MCP client config:

{
  "mcpServers": {
    "swiss-weather": {
      "command": "swiss-weather-mcp"
    }
  }
}

If you want to run it from source instead of an installed binary:

{
  "mcpServers": {
    "swiss-weather": {
      "command": "cargo",
      "args": [
        "run",
        "--quiet",
        "--manifest-path",
        "/absolute/path/to/swiss-weather-mcp/Cargo.toml"
      ]
    }
  }
}

Repository and homepage:

• https://github.com/pi-victor/swiss-weather-mcp

License:

• Apache-2.0

What It Provides

This server currently exposes these tools:

• list_weather_stations
• get_precipitation
• get_wind_speed_10min
• get_wind_gusts_10min
• get_sunshine
• get_global_radiation
• list_pollen_stations
• get_pollen_measurement
• get_local_forecast

Data Sources

The implementation currently pulls data from these upstream sources:

• MeteoSwiss / geo.admin current measurement layers for precipitation, wind, sunshine, and global radiation
• MeteoSwiss OGD local forecasting dataset for point forecast data
• MeteoSwiss OGD pollen dataset for pollen station discovery
• Copernicus CAMS via ECMWF public WMS for UV daily maximum values
• FOEN NABEL current table for current pollutant measurements

Current Limits

• Transport is stdio only. There is no HTTP server.
• air_quality_aqi is not implemented as a verified AQI feed. The server returns current pollutant measurements separately and marks AQI unavailable.
• air_quality_current is mapped to the nearest official NABEL station using static station metadata embedded in the code. The pollutant values themselves are live.
• A live cargo run end-to-end check for get_local_forecast may depend on external upstream latency.

Build And Run

Requirements:

• Rust stable

Common commands:

cargo build
cargo run
cargo test
cargo clippy --all-targets --all-features
cargo fmt

To run the server manually:

cargo run

Then write JSON-RPC requests, one per line, to stdin.

MCP Protocol

The server supports:

• initialize
• notifications/initialized
• tools/list
• tools/call

Protocol version:

• 2025-03-26

Example Initialize

Request:

{"jsonrpc":"2.0","id":1,"method":"initialize","params":{}}

Response shape:

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": {
    "protocolVersion": "2025-03-26",
    "capabilities": {
      "tools": {
        "listChanged": false
      }
    },
    "serverInfo": {
      "name": "swiss-weather-mcp",
      "version": "0.1.0"
    }
  }
}

Example Tools Call

Request:

{
  "jsonrpc": "2.0",
  "id": 2,
  "method": "tools/call",
  "params": {
    "name": "get_local_forecast",
    "arguments": {
      "point_query": "Bettwil",
      "hours": 12
    }
  }
}

Tool results are returned as MCP content blocks containing pretty-printed JSON text:

{
  "jsonrpc": "2.0",
  "id": 2,
  "result": {
    "content": [
      {
        "type": "text",
        "text": "{\n  ... tool JSON ...\n}"
      }
    ]
  }
}

Tool Reference

list_weather_stations

Lists MeteoSwiss current-weather stations based on the latest 10-minute precipitation layer.

Arguments:

• none

Returns:

• source_url: upstream JSON file URL
• updated_at: source timestamp
• station_count
• stations: array of:
  • id
  • station_name
  • coordinates_lv95.east
  • coordinates_lv95.north

get_precipitation

Returns precipitation measurements from official MeteoSwiss current layers.

Arguments:

• interval: one of 10min, 1h, 24h, 48h
• station_id: optional station filter

Returns:

• source_url
• layer
• title
• updated_at
• record_count
• records

get_wind_speed_10min

Returns the MeteoSwiss 10-minute mean wind speed layer.

Arguments:

• station_id: optional station filter

Returns the same top-level shape as get_precipitation.

get_wind_gusts_10min

Returns the MeteoSwiss 10-minute maximum 1-second wind gust layer.

Arguments:

• station_id: optional station filter

Returns the same top-level shape as get_precipitation.

get_sunshine

Returns sunshine duration measurements.

Arguments:

• interval: one of 10min, 1d
• station_id: optional station filter

Returns the same top-level shape as get_precipitation.

get_global_radiation

Returns global radiation measurements.

Arguments:

• interval: one of 10min, 1d
• station_id: optional station filter

Returns the same top-level shape as get_precipitation.

list_pollen_stations

Lists MeteoSwiss pollen stations from the pollen OGD dataset.

Arguments:

• none

Returns:

• source_url
• station_count
• stations: array of:
  • id
  • station_name

get_pollen_measurement

Returns the latest hourly measurement layer for a specific pollen species.

Arguments:

• species: one of alder, ash, beech, birch, grass, hazel, oak
• station_id: optional station filter

Returns the same top-level shape as get_precipitation.

Notes:

• The pollen layers use a missing-value sentinel (99999) which is converted to null.

get_local_forecast

Returns the latest local forecast for a point, with daily summary rows, hourly rows, computed summary blocks, UV, current pollen, and current air quality.

Arguments:

• point_query: point ID, station abbreviation, postal code, or point name
• hours: optional integer from 1 to 96, default 24

Top-level return shape:

• source_collection
• issued_at
• point
• daily_parameters
• hourly_parameters
• daily_summary_count
• hourly_breakdown_count
• daily_summary
• hourly_breakdown
• summary
• unsupported

Shared Response Shapes

Measurement Layer Responses

These tools return the same general shape:

• get_precipitation
• get_wind_speed_10min
• get_wind_gusts_10min
• get_sunshine
• get_global_radiation
• get_pollen_measurement

Top-level fields:

• source_url
• layer
• title
• updated_at
• record_count
• records

Each records item contains:

• station_id
• station_name
• value
• unit
• reference_timestamp
• altitude
• measurement_height
• coordinates_lv95
• wind_direction_degrees
• wind_direction_radian
• optional value_relative

Notes:

• Some fields may be null depending on the source layer.
• station_id matching accepts exact station ID, exact station name, or substring match on station name.

Forecast Point Resolution

get_local_forecast resolves point_query in this order:

1. exact point_id
2. exact station_abbr
3. exact postal_code
4. exact point_name
5. partial match against point_name, station_abbr, or postal_code

Ambiguous partial matches return an error.

get_local_forecast Response Contract

point

The selected point object contains:

• point_id
• point_name
• point_type
• station_abbr
• postal_code
• altitude_masl
• coordinates_wgs84.lat
• coordinates_wgs84.lon
• coordinates_lv95.east
• coordinates_lv95.north

hourly_parameters

Each item contains:

• parameter_code
• field_name
• label
• unit

The current hourly parameter set is:

• temperature_2m_c
• precipitation_hourly_mm
• precipitation_probability_3h_percent
• wind_direction_degrees
• wind_speed_kmh
• wind_gust_kmh
• weather_icon_code
• low_cloud_cover
• medium_cloud_cover
• high_cloud_cover
• sunshine_duration_minutes
• global_radiation_w_m2
• diffuse_radiation_w_m2

daily_parameters

Each item contains the same metadata fields as hourly_parameters.

The current daily parameter set is:

• temperature_min_c
• temperature_max_c
• precipitation_total_mm
• precipitation_total_10_percentile_mm
• precipitation_total_90_percentile_mm
• weather_icon_code

hourly_breakdown

An array of timeline rows. Each row contains:

• forecast_time
• zero or more hourly fields from the parameter set above

The server only includes values that were present in the source series for that timestamp.

daily_summary

An array of daily rows. Each row contains:

• forecast_date
• zero or more daily fields from the daily parameter set above

summary

summary is a derived rollup built from hourly_breakdown plus external UV, pollen, and air-quality lookups.

Fields:

• temperature_2m_c
• precipitation_hourly_mm
• precipitation_probability_3h_percent
• wind_speed_kmh
• wind_gust_kmh
• sunshine_duration_minutes
• global_radiation_w_m2
• diffuse_radiation_w_m2
• cloud_cover_fraction
• uv_index
• pollen_current
• air_quality_current
• air_quality_aqi

Numeric Summary Objects

These fields use:

{
  "min": 0.0,
  "max": 0.0,
  "mean": 0.0
}

Used for:

• temperature_2m_c
• precipitation_probability_3h_percent
• wind_speed_kmh
• wind_gust_kmh
• global_radiation_w_m2
• diffuse_radiation_w_m2
• cloud_cover_fraction.low
• cloud_cover_fraction.medium
• cloud_cover_fraction.high

Accumulation Summary Objects

These fields use:

{
  "total": 0.0,
  "max": 0.0
}

Used for:

• precipitation_hourly_mm
• sunshine_duration_minutes

uv_index

Current behavior:

• Source: Copernicus CAMS via ECMWF public WMS
• Uses the first up to 3 daily forecast dates

Available shape:

{
  "available": true,
  "source": {
    "provider": "Copernicus CAMS",
    "service": "ECMWF public WMS",
    "layer": "composition_uvindex_daily_max",
    "url": "https://eccharts.ecmwf.int/wms/"
  },
  "daily_max_summary": {
    "min": 0.0,
    "max": 0.0,
    "mean": 0.0
  },
  "daily_max_forecast": [
    {
      "forecast_date": "20260420",
      "time_utc": "2026-04-20T00:00:00Z",
      "value": 4.1,
      "nearest_grid_point": {
        "latitude": 47.2,
        "longitude": 8.4,
        "distance_km": 14.6
      }
    }
  ]
}

Unavailable shape:

{
  "available": false,
  "reason": "Copernicus CAMS UV lookup is unavailable for this point or time window. ..."
}

air_quality_current

Current behavior:

• Source: FOEN NABEL current table
• The server chooses the nearest official NABEL station using static station metadata and the forecast point LV95 coordinates

Available shape:

{
  "available": true,
  "reported_at": "Data from: 19.04.2026 23:00",
  "source": {
    "provider": "FOEN NABEL",
    "service": "Current situation table",
    "url": "https://bafu.meteotest.ch/nabel/tables/show/english"
  },
  "nearest_station": {
    "id": "BER",
    "station_name": "Bern-Bollwerk",
    "site_type": "Urban, traffic",
    "distance_km": 42.7,
    "coordinates_lv95": {
      "east": 2600170.0,
      "north": 1199990.0
    }
  },
  "measurements_ug_m3": {
    "o3": 68.0,
    "o3_daily_max": 88.0,
    "no2": 10.0,
    "pm10": 13.0,
    "pm2_5": 6.0
  }
}

Unavailable shape:

{
  "available": false,
  "reason": "Official FOEN NABEL current pollutant measurements are unavailable for this point or time window. ..."
}

pollen_current

Current behavior:

• Source: MeteoSwiss official pollen station catalog and hourly pollen measurement layers
• The server chooses the nearest official pollen station using the forecast point WGS84 coordinates

Available shape:

{
  "available": true,
  "source": {
    "provider": "MeteoSwiss",
    "service": "Official pollen measurement layers"
  },
  "nearest_station": {
    "id": "PBE",
    "station_name": "Bern",
    "distance_km": 14.2,
    "coordinates_wgs84": {
      "lat": 46.948,
      "lon": 7.4474
    }
  },
  "reference_timestamp": "2026-04-20T10:00:00Z",
  "measurements": {
    "alder": {
      "value": 12.0,
      "unit": "grains/m3",
      "reference_timestamp": "2026-04-20T10:00:00Z"
    },
    "grass": {
      "value": 31.0,
      "unit": "grains/m3",
      "reference_timestamp": "2026-04-20T10:00:00Z"
    }
  }
}

Unavailable shape:

{
  "available": false,
  "reason": "Official MeteoSwiss pollen measurements are unavailable for this point or time window. ..."
}

air_quality_aqi

Current behavior:

• There is no verified AQI feed integrated
• The field is currently returned as unavailable

Shape:

{
  "available": false,
  "reason": "No verified official AQI feed has been integrated. Current official NABEL pollutant measurements are available separately in summary.air_quality_current."
}

unsupported

unsupported is an object containing only the unavailable derived sub-features.

Possible keys:

• uv_index
• pollen_current
• air_quality_current
• air_quality_aqi

Each value is the corresponding reason string.

If all derived features are available, unsupported is an empty object.

Error Behavior

Common failure cases:

• missing required tool argument
• unsupported interval
• unsupported pollen species
• unknown tool name
• unsupported method
• no matching station or point
• ambiguous point query
• upstream request failure
• upstream decode failure

For tool calls, application errors are returned inside the tool content as:

Error: ...

JSON-RPC argument and method errors are returned as MCP error objects, for example:

• -32601 for unknown method or unknown tool
• -32602 for missing required arguments

Development Notes

• Formatting: cargo fmt
• Typecheck/build validation: cargo check
• Tests: cargo test
• Linting: cargo clippy --all-targets --all-features

The current implementation has unit tests for:

• MCP request/response serialization
• CSV parsing
• forecast asset parsing
• forecast summary derivation
• CAMS UV parsing
• compact CAMS date conversion
• NABEL table parsing
• station-name normalization
• ambiguous point resolution

Example Session

{"jsonrpc":"2.0","id":1,"method":"initialize","params":{}}
{"jsonrpc":"2.0","id":2,"method":"tools/list","params":{}}
{"jsonrpc":"2.0","id":3,"method":"tools/call","params":{"name":"get_local_forecast","arguments":{"point_query":"Bettwil","hours":12}}}

Repository Layout

• src/main.rs: request handling, tool implementations, forecast parsing, UV and air-quality integration, tests
• src/mcp_engine.rs: MCP protocol types, tool metadata, shared CSV and source types
• Cargo.toml: dependencies and crate metadata
• README.md: package readme and user-facing project documentation