Wind Speed

Description

When You See or Feel This Effect

Wind (mph)

Wind (km/h)

Calm

Smoke goes straight up

less than 1

less than 2

Light air

Wind direction is shown by smoke drift but not by wind vane

1-3

2-5

Light breeze

Wind is felt on the face; leaves rustle; wind vanes move

4-7

6-11

Gentle breeze

Leaves and small twigs move steadily; wind extends small flags straight out

8-12

12-19

Moderate breeze

Wind raises dust and loose paper; small branches move

13-18

20-29

Fresh breeze

Small trees sway; waves form on lakes

19-24

30-39

Strong breeze

Large branches move; wires whistle; umbrellas are difficult to use

25-31

40-50

Moderate gale

Whole trees are in motion; walking against the wind is difficult

32-38

51-61

Fresh gale

Twigs break from trees; walking against the wind is very difficult

39-46

62-74

Strong gale

Buildings suffer minimal damage; roof shingles are removed

47-54

75-87

Whole gale

Trees are uprooted

55-63

88-101

Violent storm

Widespread damage

64-72

102-116

Hurricane

Widespread destruction

73+

117+