SolriseThe Beaufort wind scale: what wind speeds feel like
The Beaufort wind scale describes wind by what it does, on a scale from 0 (Calm) to 12 (Hurricane force). For example, 19 to 24 mph is a Fresh breeze, when small trees in leaf begin to sway, and 39 to 46 mph is a Gale, when walking is difficult.
What the Beaufort scale is
Wind is how fast air is moving near the surface, and which direction it is coming from. A number like "19 mph" is precise but hard to picture. The Beaufort scale fixes that by pairing each range of speeds with what you can actually see happening around you, from smoke rising straight up to trees being uprooted.
The Beaufort wind scale
| Force | Name | mph | km/h | What it looks like |
|---|---|---|---|---|
| 0 | Calm | under 1 | under 2 | Smoke rises straight up. |
| 1 | Light air | 1 to 3 | 2 to 5 | Smoke drifts, but wind vanes don't move. |
| 2 | Light breeze | 4 to 7 | 6 to 11 | You feel it on your face and leaves rustle. |
| 3 | Gentle breeze | 8 to 12 | 12 to 19 | Leaves and small twigs keep moving; light flags stretch out. |
| 4 | Moderate breeze | 13 to 18 | 20 to 29 | Dust and loose paper lift; small branches move. |
| 5 | Fresh breeze | 19 to 24 | 30 to 39 | Small trees in leaf begin to sway. |
| 6 | Strong breeze | 25 to 31 | 40 to 50 | Large branches move and umbrellas are hard to use. |
| 7 | Near gale | 32 to 38 | 51 to 62 | Whole trees sway and walking into the wind is hard. |
| 8 | Gale | 39 to 46 | 63 to 75 | Twigs break off trees and walking is difficult. |
| 9 | Strong gale | 47 to 54 | 76 to 88 | Slight structural damage, like shingles blowing off. |
| 10 | Storm | 55 to 63 | 89 to 102 | Trees uprooted and considerable damage. |
| 11 | Violent storm | 64 to 72 | 103 to 117 | Widespread damage. |
| 12 | Hurricane force | 73 and up | 118 and up | Devastating, widespread damage. |
Source: Beaufort wind force scale, land descriptions as used by the National Weather Service. km/h converted from mph and rounded.
Why wind changes
Wind picks up when there is a bigger difference in pressure between two nearby areas: the atmosphere is just trying to even that out. That is why a strong storm system, with very low pressure near its center, brings strong wind with it.
Where you stand matters too. Airport wind is measured over open ground, so wooded trails and city streets usually feel calmer, while ridges and open beaches feel stronger. Coastal wind can also differ a lot from inland forecasts because of the water.
What wind means for you
Everyday
Above about 25 mph, umbrellas turn inside out and loose patio furniture becomes a problem. If you are heading out for a run or a walk, a headwind on the way out is a tailwind on the way back, so expect your easy effort to feel slower into the wind.
Outdoors
Start runs and rides into the wind so the tailwind helps on the tired half home. Above about 20 mph, ridgelines and exposed summits get much gustier than the trailhead, and crosswinds can push a bike sideways.
Flying
Check the gust spread, not just the average: a big gap between steady wind and gusts is what upsets small aircraft on landing and pushes drones off station. Compare the crosswind component with your aircraft's demonstrated limit, and remember wind is usually stronger at 400 ft than on the ground.
Common questions
How strong is a 20 mph wind?
20 mph is a Fresh breeze, Beaufort force 5 (19 to 24 mph): small trees in leaf begin to sway.
What wind speed is a gale?
On the Beaufort scale, a Gale is force 8, 39 to 46 mph (63 to 75 km/h). Twigs break off trees and walking is difficult.
What wind speed is too strong for an umbrella?
Above about 25 mph, a Strong breeze on the Beaufort scale, umbrellas are hard to use and often turn inside out.
Related
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