Beaufort Scale

Kilometres per Hour	Miles per Hour	Beafort
0	0	0
2 - 6	1 - 3	1
7 - 12	3 - 8	2
13 - 20	8 - 13	3
21 - 30	13-19	4
31 - 40	19 - 25	5
41 - 50	25 - 31	6
51 - 61	32 - 38	7
62 - 74	39 - 46	8
75 - 89	47 - 55	9
90 - 103	56 - 64	10
104 - 119	65-74	11
120 +	75 +	12

The Beaufort scale was named after Rear Admiral Sir Francis Beaufort born in County Meath, Ireland 24th May 1774. In addition to creating the wind force scale bearing his name, he carried out hydrographic surveys which are used to this day.