Wind Speed Chart

Force Index	Description	When you see or feel this effect	Wind (mph)	Wind (km/h)
00	Calm	Smoke goes straight up	less than 1	less than 2
01	Light air	Wind direction is shown by smoke drift but not by wind vane	1-3	2-5
02	Light breeze	Wind is felt on the face; leaves rustle; wind vanes move	4-7	6-11
03	Gentle breeze	Leaves and small twigs move steadily; wind extends small flags straight out	8-12	12-19
04	Moderate breeze	Wind raises dust and loose paper; small branches move	13-18	20-29
05	Fresh breeze	Small trees sway; waves form on lakes	19-24	30-39
06	Strong breeze	Large branches move; wires whistle; umbrellas are difficult to use	25-31	40-50
07	Moderate gale	Whole trees are in motion; walking against the wind is difficult	32-38	51-61
08	Fresh gale	Twiges break from trees; walking against the wind is very difficult	39-46	62-74
09	String gale	Buildings suffer minimal damage; roof shingles are removed	47-54	75-87
10	Whole gale	Trees are uprooted	55-63	88-101
11	Violent storm	Windspeed damage	64-72	102-116
12	Hurricane	Windspeed destruction	73+	117+