0–1

Calm

Smoke rises straight up

0–5.5

(0–3)

2–3

Light breeze

Leaves rustle and wind vane moves slightly

5.6–19

(4–12)

4–5

Moderate breeze

Loose paper blows around

20–38

(13–24)

6–7

Strong breeze

Open umbrellas are hard to hold and flip over

39–61

(25–38)

8–9

Gale

Walking against the wind is extremely difficult

62–88

(39–54)

10–11

Storm (whole gale)

Trees are uprooted

89–117

(55–73)

≥ 12

Hurricane force

Widespread damage

> 117

(> 73)