Beaufort Wind Scale Guide

🌬️ Beaufort wind scale

Force	Name	Knots	mph	km/h	On land	At sea	What can I fly?
0	Calm	< 1 kt	< 1 mph	< 1 km/h	Calm; smoke rises vertically.	Sea like a mirror.	No wind to fly — nothing will stay up.
1	Light air	1–3 kt	1–3 mph	1–5 km/h	Smoke drifts, showing wind direction; vanes do not move.	Ripples without crests.	Barely flyable — only ultralight or indoor kites lift, and only briefly.
2	Light breeze	4–6 kt	4–7 mph	6–11 km/h	Wind felt on face; leaves rustle; vanes begin to move.	Small wavelets, glassy crests.	Good for light-wind and large delta single-line kites.
3	Gentle breeze	7–10 kt	8–12 mph	12–19 km/h	Leaves and small twigs in constant motion; light flags extend.	Large wavelets; scattered whitecaps.	Ideal all-round — most single-line and beginner sport kites fly beautifully.
4	Moderate breeze	11–16 kt	13–18 mph	20–28 km/h	Raises dust and loose paper; small branches move.	Small waves; frequent whitecaps.	Excellent for sport and stunt kites; single-line kites pull firmly.
5	Fresh breeze	17–21 kt	19–24 mph	29–38 km/h	Small trees in leaf begin to sway.	Moderate waves; many whitecaps, some spray.	Strong-wind sport kites and power/traction kites — experienced flyers only.
6	Strong breeze	22–27 kt	25–31 mph	39–49 km/h	Large branches move; whistling in wires; umbrellas hard to use.	Large waves; white foam crests, more spray.	Experts only — small power/traction kites with very high pull; risky.
7	Near gale	28–33 kt	32–38 mph	50–61 km/h	Whole trees in motion; hard to walk against the wind.	Sea heaps up; foam blown in streaks.	Too strong for almost everyone — dangerous; do not fly.
8	Gale	34–40 kt	39–46 mph	62–74 km/h	Twigs break off trees; walking impeded.	Moderately high waves; crests break into spindrift.	Do not fly — dangerous conditions.
9	Strong gale	41–47 kt	47–54 mph	75–88 km/h	Slight structural damage; chimney pots and slates removed.	High waves; dense foam; spray affects visibility.	Do not fly — dangerous conditions.
10	Storm	48–55 kt	55–63 mph	89–102 km/h	Trees uprooted; considerable structural damage (rare inland).	Very high waves; sea white with foam.	Do not fly — dangerous conditions.
11	Violent storm	56–63 kt	64–72 mph	103–117 km/h	Widespread damage (very rare).	Exceptionally high waves; sea covered in foam.	Do not fly — dangerous conditions.
12	Hurricane force	≥ 64 kt	≥ 73 mph	≥ 118 km/h	Devastation.	Air filled with foam and spray; sea completely white.	Do not fly — dangerous conditions.

Wind bands are the WMO standard, anchored in knots; the mph and km/h ranges are the accepted published values. The “what can I fly?” column is general guidance. Kite flying and kiteboarding are wind sports with real risks — get proper instruction, watch for gusts, and use your own judgement.

From calm to hurricane, at a glance

The Beaufort scale is handy precisely because you can read it without instruments: leaves rustling is force 2, whole trees swaying is force 6, and hard-to-walk-against wind is force 7. For a flyer, learning to eyeball a force from the world around you is a genuinely useful skill.

Have a number from a forecast or wind meter instead? Drop it into the Wind Speed Converter to get the force and a fly-or-not recommendation directly.

❓ Frequently Asked Questions

What is the Beaufort wind scale?

It is a 13-step scale, force 0 to force 12, that relates wind speed to observable effects on land and sea. Admiral Francis Beaufort standardised it in 1805 for the Royal Navy. Force 0 is calm (under 1 knot), force 6 a strong breeze (22–27 knots), force 8 a gale (34–40 knots), and force 12 hurricane force (64 knots and above).

How are the knot, mph, and km/h ranges related?

The scale is defined in knots (the WMO standard), and the mph and km/h columns are the accepted published equivalents. As a rule of thumb, 1 knot ≈ 1.15 mph ≈ 1.85 km/h. This guide shares its dataset with the Wind Speed Converter, so a force here always matches the force it reports.

Which forces are good for flying kites?

Broadly: force 0 is too calm; forces 2–4 (about 4–16 knots) are the sweet spot for most single-line and sport kites; force 5 (17–21 knots) suits strong-wind and power kites for experienced flyers; force 6 (22–27 knots) is experts-only; and force 7 and above (28 knots up) is too strong and dangerous. The 'what can I fly?' column summarises this per force.

Can I rely on this to decide whether to fly?

Use it as a reference, not a rule. Local gusts, terrain, and your kite and skill all matter. Kite flying and kiteboarding are wind sports with real risks — get proper instruction, check the real wind on the day, and use your own judgement.