Wind: Beaufort Scale & Monsoons

1805 to today · from a breeze to a storm

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Before anemometers were everywhere, sailors measured wind with their eyes — and the Beaufort scale (1805, Francis Beaufort) is still the best way to "feel" a km/h number. Every city page of ours shows the Beaufort number next to the wind speed; here is the full table.

LevelSpeedNameWhat it looks like at sea and on land
0< 1 km/hCalmSmoke rises vertically; leaves do not stir
11–5 km/hLight airWind direction shown only by smoke drift
26–11 km/hLight breezeLeaves and small twigs in constant motion
312–19 km/hGentle breezeSmall branches move; flags extend
420–28 km/hModerate breezeDust and loose paper rise; thin branches bend
529–38 km/hFresh breezeSmall trees sway; whitecaps form on waves
639–49 km/hStrong breezeLarge branches move; walking an umbrella is hard
750–61 km/hNear galeWhole trees sway; walking into the wind is difficult
862–74 km/hGaleTwigs break off; roof tiles and cladding start to lift
975–88 km/hStrong galeTrees uprooted; moderate structural damage
1089–102 km/hStormWidespread damage; trees snapped or toppled
11103–112 km/hViolent stormExtensive damage across built-up areas
12> 112 km/hHurricane forceTotal destruction; exceptional sea waves

Malaysia’s two monsoons

The wind in our region reverses direction twice a year. The Southwest Monsoon (May–September) is drier on the Peninsula but wets offshore western Sabah; the Northeast Monsoon (November–March) sends monsoon rain to the Peninsula’s east coast (Kelantan, Terengganu, Pahang) and regularly floods Kota Bharu & Kuantan while Kuala Lumpur and Kuching stay comparatively dry. Weak monsoon wind plus smoke from burning = haze (code 721) — which is why June–September is the bad-AQI season, not the rainy season.

Practical danger

Beaufort 7+ = hard to ride a motorcycle in storm rain (sideways force plus slippery tyres). Beaufort 9+ = staying indoors is the right call; falling trees are the number-one storm killer in the subtropics. The live wind numbers on our extremes page always show which cities have already reached those levels.

Wind direction

A reading of "wind 240°" means the wind comes from 240° (southwest) — a meteorological convention that confuses many people. Leeward is the sheltered side; that is why orographic rain falls on Sarawak’s windward slope and stays dry in the rain shadow behind it.

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