Description

Wind Speed
MPH

Observable Effects on the Environment

Calm

less than 1

Smoke will rise vertically.

Light Air

1-3

Rising smoke drifts, weather vane is inactive.

Light Breeze

4-7

Leaves rustle, can feel wind on your face

Gentle Breeze

8-12

Leaves and twigs move around.

Moderate Breeze

13-18

Moves thin branches, raises dust and paper.

Fresh Breeze

19-24

Trees sway.

Strong Breeze

25-31

Large tree branches move, open wires (such as telegraph wires) begin to "whistle", umbrellas are difficult to keep under control.

Moderate Gale

32-38

Large trees begin to sway, noticeably difficult to walk.

Fresh Gale

39-46

Twigs and small branches are broken from trees, walking into the wind is very difficult.

Strong Gale

47-54

Slight damage occurs to buildings, shingles are blown off of roofs.

Whole Gale

55-63

Large trees are uprooted, building damage is considerable.

Storm

64-75

Extensive widespread damage. These typically occur only at sea, and rarely inland.

Hurricane

above 75

Extreme destruction.