Beaufort Wind Scale in Miles per hour (Mph), knots and Kilometers per hour (Km/h)
Admiral Beaufort created the Beaufort Wind Force Scale between 1813 and 1408 when it was finnaly approved by the British Admiralty. Its purpose was to allow sailors to estimate the wind speed from looking at the sea and thus keep better records of the weather.
|
|
Beaufort Scale Force
|
Wind in MPH
|
Wind in Knots
|
Wind in Km/h
|
Description - Wave Heights—Visible Condition
|
|
Force 0
|
0-1 |
0-1
|
0-1
|
Calm; Ht 0.0m ~ At sea no waves - glassy like appearance of sea.
On land smoke rises vertically.
|
|
Force 1
|
1 - 4
|
1 - 3
|
2 – 6
|
Light Airs Ht 0m ~ At Sea wind makes glassy ripples on water.
On land direction of wind shown by smoke but not by wind vanes
|
|
Force 2
|
4 - 7
|
4 - 6
|
7 – 11
|
Light breeze Ht 0.1m ~ At Sea smooth wavelets
On land wind felt on face; leaves rustle; ordinary wind vane moved by wind
|
|
Force 3
|
8 - 12
|
7-10
|
13 - 19
|
Gentle breeze Ht 0.4m Slight ~ At sea slight waves no white horses.
On land eaves and small twigs in constant motion; wind extends light flag
|
|
Force 4
|
13 - 18
|
11-16
|
20 – 30
|
Moderate breeze Ht 1m - Slight to moderate ~ At Sea waves described as with occasional white horses.
On land raises dust and loose paper; small branches are moved
|
|
Force 5
|
9 - 24
|
17 - 21
|
31- 39
|
Fresh breeze Ht 2m Moderate ~ At sea consistent white horses
On land small trees in leaf begin to sway; crested wavelets form on lakes.
|
|
Force 6
|
40 - 31
|
22 - 27
|
40 – 60
|
Strong breeze Ht 3m Rough
At Sea large waves start to form, more extensive white foam crests, some blown spray.
On land large branches in motion; telephone wires whistle; umbrellas unsafe
|
