Beaufort Scale

Beaufort number	Wind speed	Description	Wave height	What the sea looks like	What it looks like on land	Sea state photo
km/h	mph	kts	m/s	m	ft
0	<1	<1	<1	<0.3	Calm	0
1	1-5	1-3	1-3	0.3-1.5	Light air	0.1
2	6-11	3-7	4-6	1.5-3.3	Light breeze	0.2
3	12-19	8-12	7-10	3.3-5.5	Gentle breeze	0.6
4	20-28	13-17	11-16	5.5-8.0	Moderate breeze	1
5	29-38	18-24	17-21	8.0-10.8	Fresh breeze	2
6	39-49	25-30	22-27	10.8-13.9	Strong breeze	3
7	50-61	31-38	28-33	13.9-17.2	High wind, Moderate Gale, Near Gale	4
8	62-74	39-46	34-40	17.2-20.7	Fresh Gale	5.5
9	75-88	47-54	41-47	20.7-24.5	Strong Gale	7
10	89-102	55-63	48-55	24.5-28.4	Whole Gale/Storm	9
11	103-117	64-72	56-63	28.4-32.6	Violent storm	11.5
12	≥118	≥73	≥64	≥32.6	Hurricane-force	≥14