0 *** <1 (<1.6)***Calm: Still: Smoke will rise vertically.
1***1-3(1.6-4.8)*** Light Air: Rising smoke drifts, weather vane is inactive.
2***4-7(6.4-11.3)***Light Breeze: Leaves rustle, can feel wind on your face, weather vane is inactive.
3***8-12(12.9-19.3)***Gentle Breeze: Leaves and twigs move around. Light weight flags extend.
4***13-28 (20.9-29.0)***Moderate Breeze: Moves thin branches, raises dust and paper.
5***19-24 (30.6-38.6)***Fresh Breeze: Moves trees sway.
6***25-31(40.2-50.0) ***Strong Breeze: Large tree branches move, open wires (such as telegraph wires) begin to "whistle", umbrellas are difficult to keep under control.
7***32-38 (51.5-61.2)***Moderate Gale: Large trees begin to sway, noticeably difficult to walk.
8***39-46(62.8-74.0)***Fresh Gale: Twigs and small branches are broken from trees, walking into the wing is very difficult.
9***47-54(75.6-86.9)***Strong Gale: Slight damage occurs to buildings, shingles are blown off of roofs.
10***55-63 (88.5-101.4)***Whole Gale: Large trees are uprooted, building damage is considerable.
11***64-72 (103.0-115.9)***Storm: Extensive widespread damage. These typically occur only at sea, and rarely inland.
12***>73 (>115.9)***Hurricane: Extreme destruction.
NOTE: The Beaufort number is also referred to as a "Force" number, for example,
"Force 10 Gale".
* To calculate knots, divide miles/hour by 1.15.
* Small craft advisories are usually issued when force 6 is reached.
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