less than 1 mph

Calm; smoke rises vertically

1 - 3 mph

Direction of wind shown by smoke drift,
but not by wind vanes

4 - 7 mph

Wind felt on face; leaves rustle;
ordinary vane moved by wind

8 - 12 mph

Leaves and small twigs in constant motion;
wind extends light flag

13 - 18 mph

Raises dust and loose paper;
small branches are moved

19 - 24 mph

Small trees in leaf begin to sway;
crested wavelets form on inland waters

25 - 31 mph

Large branches in motion;
whistling heard in telephone wires

32 - 38 mph

Whole trees in motion;
inconvenience felt walking against the wind

39 - 46 mph

Breaks twigs off trees;
wind generally impedes progress

47 - 54 mph

Slight structural damage
occurs

Severe begins at 58 mph

55 - 63 mph

Damage to chimneys and TV antennas;
pushes over shallow rooted trees

64 - 74 mph

Rarely experienced;
structural damage becomes possible

above 75 mph

Very rarely experienced