Type of wind

Description

Visible signs

0—Calm

less than 1 mph (0 m/s)

Smoke rises vertically

1—Light air

1 - 3 mph 0.5-1.5 m/s

Smoke drifts with air, weather vanes inactive

2—Light breeze

4 - 7 mph 2-3 m/s

Weather vanes active, wind felt on face, leaves rustle

3—Gentle breeze

8 - 12 mph 3.5-5 m/s

Leaves & small twigs move, light flags extend

4—Moderate breeze

13 - 18 mph 5.5-8 m/s

Small branches sway, dust & loose paper blows about

5—Fresh breeze

19 - 24 mph 8.5-10.5 m/s

Small trees sway, waves break on inland waters

6—Strong breeze

25 - 31 mph 11-13.5 m/s

Large branches sway, umbrellas difficult to use

7—Moderate gale

32 - 38 mph 14-16.5 m/s

Whole trees sway, difficult to walk against wind

8—Fresh gale

39 - 46 mph 17-20 m/s

Twigs broken off trees, walking against wind very difficult

9—Strong gale

47 - 54 mph 20.5-23.5 m/s

Slight damage to buildings, shingles blown off roof

10—Whole gale

55 - 63 mph 24-27.5 m/s

Trees uprooted, considerable damage to buildings

11—Storm

64 - 73 mph 28-31.5 m/s

Widespread damage, very rare occurrence

12—Hurricane

over 73 mph over 32 m/s

Violent destruction