The Beaufort scale for ecologists (Jones & Reynolds 2000)
Beaufort number Name of wind Observable features Field ecologists’ impressions Velocity (km/hour)
0 Calm Smoke rises vertically You’re having a good time <2
1 Light air Smoke drifts downwind. Wind does not move wind vane You’re still having a good time 2 to 5
2 Light breeze Wind felt on face; leaves rustle. Vane moved by wind It’s a bit tricky to photograph insects on plants 6 to 12
3 Gentle breeze Leaves and twigs in constant motion; wind extends light flag At least there are no biting insects to contend with 13 to 20
4 Moderate breeze Raises dust and loose paper; small branches are moved It’s hard to keep your notes from flapping 21 to 29
5 Fresh breeze Small trees in leaf begin to sway; crested wavelets form on inland waters You prefer to work in sheltered places 30 to 39
6 Strong breeze Large branches in motion; whistling heard in telegraph wires; umbrellas used with difficulty Your tripod is blowing over 40 to 50
7 Moderate gale Whole trees in motion; inconvenience felt in walking against wind You’re doing this for the good of science 51 to 61
8 Fresh gale Twigs break off trees; progress generally impeded You’re not being paid enough 62 to 74
9 Strong gale Slight structural damage occurs (chimney pots and slate removed) You’re thinking about where you’ve parked your vehicle 75 to 87
10 Whole gale Seldom experienced inland; trees uprooted; considerable structural damage occurs You’re wondering how you’ll get home 88 to 101
11 Storm Very rarely experienced; accompanied by widespread destruction You’re wondering what shape your home is in 102 to 121
12 Hurricane At sea, visibility is badly affected by foam and spray and the sea surface is completely white Time to find a new study site >121

Jones J.C. and Reynolds J.D. (2000) Environmental variables, In: Ecological Census Techniques: A Handbook (ed. W.J. Sutherland)
Cambridge University Press, Cambridge, 281 – 316.