Κλίμακα Beaufort

BEAUFORT SCALE
Observable Effects	International Description	Beaufort Number	Wind Speed
			meters/sec m/s	km/hour km/h	miles/hour mph	knots kt
Air calm; smoke rises vertically	Calm	0	< 0.5	< 1	< 1	< 1
Direction of wind shown by smoke drift but not by wind vanes	Light Air	1	0.5-1.5	1-5	1-3	1-3
Wind felt on face; leaves rustle; wind vanes moved by wind	Light Breeze	2	2-3	6-11	4-7	4-6
Leaves and small twigs in continual motion; wind extends light flags	Gentle Breeze	3	4-5	12-19	8-12	7-10
Raises dust, loose paper; moves small branches	Moderate Breeze	4	6-8	20-29	13-18	11-15
Small trees in leaf begin to sway; white crested wavelets form on inland waters	Fresh Breeze	5	9-10	30-39	19-24	16-21
Large branches in motion; umbrellas used with difficulty; telephone wires "whistle"	Strong Breeze	6	11-13	40-50	25-31	22-27
Whole trees in motion; inconvenience felt walking against wind	Moderate or Near Gale	7	14-17	51-61	32-38	28-33
Breaks twigs off trees; wind generally impedes progress	Gale or Fresh Gale	8	18-20	62-74	39-46	34-40
Slight structural damage occurs	Strong Gale	9	21-24	75-87	47-54	41-47
trees uprooted; considerable structural damage occurs	Whole Gale or Storm	10	25-28	88-101	55-63	48-55
Widespread damage	Violent Storm	11	29-33	102-118	64-73	56-63
Devastation	Hurricane	12	> 33	> 118	> 73	> 64
[ 1 mile = 1609 m ]   [ 1 nautical mile = 1852 m ]   [ 1 knot = 1 nautical mile per hour ]