Number |
Name |
MPH |
Description |
0 | calm | less than 1 | calm; smoke rises
vertically | |
1 | light air | 1-3 | direction of wind
shown by smoke but not by wind vanes | |
2 | light breeze | 4-7 | wind felt on face;
leaves rustle; ordinary vane moved by wind | |
3 | gentle breeze | 8-12 | leaves and small
twigs in constant motion; wind extends light flag | |
4 | moderate breeze | 13-18 | raises dust and
loose paper; small branches are moved | |
5 | fresh breeze | 19-24 | small trees in leaf
begin to sway; crested waves form on inland waters | |
6 | strong breeze | 25-31 | large branches in
motion; telegraph wires whistle; umbrellas used with difficulty | |
7 | moderate gale (or near gale) | 32-38 |
whole trees in motion; inconvenience in walking against wind | |
8 | fresh gale | 39-46 | breaks twigs off
trees; generally impedes progress | |
9 | strong gale | 47-54 | slight structural
damage; chimney pots and slates removed | |
10 | whole gale (or storm) | 55-63 |
trees uprooted; considerable structural damage occurs | |
11 | storm (or violent storm) | 64-72 |
very rarely experienced; accompanied by widespread damage | |
12 | hurricane | 73-136 |
devastation occurs | |