Beaufort Scale

The wind speeds shown below are those measured by an anemometer at a height of ten metres above the ground. At two metres above the ground the wind speed maybe 50 – 70% less than those shown in this table.

Wind Force Description km/h Effect
0 Calm <1 Smoke rises vertically
1 Light Air 1 - 5 Direction shown by smoke drift but not by wind vanes
2 Light Breeze 6 -11 Wind felt on face; leaves rustle; wind vane moved by wind
3 Gentle Breeze 12 - 19 Leaves and small twigs in constant motion; light flags extended
4 Moderate Breeze 20 - 28 Raises dust and loose paper; small branches moved.
5 Fresh Breeze 29 - 38 Small trees in leaf begin to sway; crested wavelets form on inland waters.
6 Strong Breeze 39 - 49 Large branches in motion; whistling heard in telegraph wires; umbrellas used with difficulty.
7 Near Gale 50 - 61 Whole trees in motion; inconvenience felt when walking against the wind.
8 Gale 62 - 74 Twigs break off trees; generally impedes progress.
9 Strong Gale 75 - 88 Slight structural damage (chimney pots and slates removed).
10 Storm 89 - 102 Seldom experienced inland; trees uprooted; considerable structural damage
11 Violent Storm 103 - 117 Very rarely experienced; accompanied by widespread damage.
12 Hurricane 118 plus Devastation