Beaufort scale

Table columns:
Beaufort number
Description
Wind speed
Wave height
Sea conditions
Land conditions
Sea state photo
Associated warning flag

Table rows:
cells: 0
Calm
< 1 km/h
0 m
Sea like a mirror
Smoke rises vertically.
cells: 0
< 1 mph
cells: 0
< 1 knot
0 ft
cells: 0
< 0.3 m/s
cells: 1
Light air
1–5 km/h
0–0.2 m
Ripples with appearance of scales are formed, without foam crests
Direction shown by smoke drift but not by wind vanes.
cells: 1
1–3 mph
cells: 1
1–3 knots
0–1 ft
cells: 1
0.3–1.5 m/s
cells: 2
Light breeze
6–11 km/h
0.2–0.5 m
Small wavelets still short but more pronounced; crests have a glassy appearance but do not break
Wind felt on face; leaves rustle; wind vane moved by wind.
cells: 2
4–7 mph
cells: 2
4–6 knots
1–2 ft
cells: 2
1.6–3.3 m/s
cells: 3
Gentle breeze
12–19 km/h
0.5–1 m
Large wavelets; crests begin to break; foam of glassy appearance; perhaps scattered white horses
Leaves and small twigs in constant motion; light flags extended.
cells: 3
8–12 mph
cells: 3
7–10 knots
2–3.5 ft
cells: 3
3.4–5.5 m/s
cells: 4
Moderate breeze
20–28 km/h
1–2 m
Small waves becoming longer; fairly frequent white horses
Raises dust and loose paper; small branches moved.
cells: 4
13–18 mph
cells: 4
11–16 knots
3.5–6 ft
cells: 4
5.5–7.9 m/s
cells: 5
Fresh breeze
29–38 km/h
2–3 m
Moderate waves taking a more pronounced long form; many white horses are formed; chance of some spray
Small trees in leaf begin to sway; crested wavelets form on inland waters.
cells: 5
19–24 mph
cells: 5
17–21 knots
6–9 ft
cells: 5
8–10.7 m/s
cells: 6
Strong breeze
39–49 km/h
3–4 m
Large waves begin to form; the white foam crests are more extensive everywhere; probably some spray
Large branches in motion; whistling heard in telegraph wires; umbrellas used with difficulty.
cells: 6
25–31 mph
cells: 6
22–27 knots
9–13 ft
cells: 6
10.8–13.8 m/s
cells: 7
High wind, moderate gale, near gale
50–61 km/h
4–5.5 m
Sea heaps up and white foam from breaking waves begins to be blown in streaks along the direction of the wind; spindrift begins to be seen
Whole trees in motion; inconvenience felt when walking against the wind.
cells: 7
32–38 mph
cells: 7
28–33 knots
13–19 ft
cells: 7
13.9–17.1 m/s
cells: 8
Gale, fresh gale
62–74 km/h
5.5–7.5 m
Moderately high waves of greater length; edges of crests break into spindrift; foam is blown in well-marked streaks along the direction of the wind
Twigs break off trees; generally impedes progress.
cells: 8
39–46 mph
cells: 8
34–40 knots
18–25 ft
cells: 8
17.2–20.7 m/s
cells: 9
Strong/severe gale
75–88 km/h
7–10 m
High waves; dense streaks of foam along the direction of the wind; sea begins to roll; spray affects visibility
Slight structural damage (chimney pots and slates removed).
cells: 9
47–54 mph
cells: 9
41–47 knots
23–32 ft
cells: 9
20.8–24.4 m/s
cells: 10
Storm,[7] whole gale
89–102 km/h
9–12.5 m
Very high waves with long overhanging crests; resulting foam in great patches is blown in dense white streaks along the direction of the wind; on the whole the surface of the sea takes on a white appearance; rolling of the sea becomes heavy; visibility affected
Seldom experienced inland; trees uprooted; considerable structural damage.
cells: 10
55–63 mph
cells: 10
48–55 knots
29–41 ft
cells: 10
24.5–28.4 m/s
cells: 11
Violent storm
103–117 km/h
11.5–16 m
Exceptionally high waves; small- and medium-sized ships might be for a long time lost to view behind the waves; sea is covered with long white patches of foam; everywhere the edges of the wave crests are blown into foam; visibility affected
Very rarely experienced; accompanied by widespread damage.
cells: 11
64–72 mph
cells: 11
56–63 knots
37–52 ft
cells: 11
28.5–32.6 m/s
cells: 12
Hurricane force [7]
≥ 118 km/h
≥ 14 m
The air is filled with foam and spray; sea is completely white with driving spray; visibility very seriously affected
Devastation.
cells: 12
≥ 73 mph
cells: 12
≥ 64 knots
≥ 46 ft
cells: 12
≥ 32.7 m/s
cells: References: Met Office,[8] Royal Meteorological Society,[9] Encyclopædia Britannica[10]
References: Met Office,[8] Royal Meteorological Society,[9] Encyclopædia Britannica[10]
References: Met Office,[8] Royal Meteorological Society,[9] Encyclopædia Britannica[10]
References: Met Office,[8] Royal Meteorological Society,[9] Encyclopædia Britannica[10]
References: Met Office,[8] Royal Meteorological Society,[9] Encyclopædia Britannica[10]
References: Met Office,[8] Royal Meteorological Society,[9] Encyclopædia Britannica[10]
References: Met Office,[8] Royal Meteorological Society,[9] Encyclopædia Britannica[10]
References: Met Office,[8] Royal Meteorological Society,[9] Encyclopædia Britannica[10]

Questions about this table:
originalText: description given to zero on the beaufort scale
answer: answerTexts: Calm