Beaufort Scale (Wind Speed)


This Beaufort Scale is to be used as a guide.


Force Speed Name Conditions at Sea Conditions on Land

knots

km/h

mi/h

0

< 1

< 2

< 1
 Calm Sea like a mirror. Smoke rises vertically.

1

1-3

1-5

1-4
 Light air Ripples only. Smoke drifts and leaves rustle.

2

4-6

6-11

5-7
 Light breeze Small wavelets (0.2 m). Crests have a glassy appearance. Wind felt on face.

3

7-10

12-19
  8-11 Gentle breeze Large wavelets (0.6 m), crests begin to break. Flags extended, leaves move. 

4

11-16

20-29

12-18
 Moderate breeze Small waves (1 m), some whitecaps. Dust and small branches move.

5

17-21

30-39

19-24
 Fresh breeze Moderate waves (1.8 m), many whitecaps. Small trees begin to sway.

6

22-27

40-50

25-31
 Strong breeze Large waves (3 m), probably some spray. Large branches move, wires whistle, umbrellas are difficult to control.

7

28-33

51-61

32-38
 Near gale Mounting sea (4 m) with foam blown in streaks downwind. Whole trees in motion, inconvenience in walking.

8

34-40

62-74

39-46
 Gale Moderately high waves (5.5 m), crests break into spindrift. Difficult to walk against wind. Twigs and small branches blown off trees.

9

41-47

76-87

47-54
 Strong gale High waves (7 m), dense foam, visibility affected. Minor structural damage may occur (shingles blown off roofs).

10

48-55

88-102

55-63
 Storm Very high waves (9 m), heavy sea roll, visibility impaired. Surface generally white. Trees uprooted, structural damage likely.

11

56-63

103-118

64-73
 Violent storm  Exceptionally high waves (11 m), visibility poor. Widespread damage to structures.

12

64+

119+

74+
 Hurricane 14 m waves, air filled with foam and spray, visibility bad. Severe structural damage to buildings, wide spread devastation.

Florida Offshore Weather receives it's data from the NOAA and includes wind, wave, and other marine data collected by the NOAA National Data Buoy Center (NDBC). The data are collected from NDBC moored buoys and from C-MAN (Coastal-Marine Automated Network) stations located on piers, offshore towers, lighthouses, and beaches. Parameters reported by both buoys and C-MAN stations include air temperature and pressure, wind speed and direction, wind gust, and sea surface temperature.