| Beaufort scale number
|| Descriptive term
|| Units in km/h
|| Units in knots
|| Description on Land
|| Description at Sea
|| Smoke rises vertically
|| Sea like a mirror.
||19 km/h or less
||10 knots or less
|| Wind felt on face; leaves rustle; ordinary vanes moved by wind.
|| Small wavelets, ripples formed but do not break: A glassy appearance maintained.
||20 - 29 km/h
|| Raises dust and loose paper; small branches are moved.
|| Small waves - becoming longer; fairly frequent white horses.
||30 - 39 km/h
|| Small trees in leaf begin to sway; crested wavelets form on inland waters
|| Moderate waves, taking a more pronounced long form; many white horses are formed - a chance of some spray
||40 - 50 km/h
|| Large branches in motion; whistling heard in telephone wires; umbrellas used with difficulty.
|| Large waves begin to form; the white foam crests are more extensive with probably some spray
||51 - 62 km/h
|| Whole trees in motion; inconvenience felt when walking against wind.
|| Sea heaps up and white foam from breaking waves begins to be blown in streaks along direction of wind.
||63 - 75 km/h
|| Twigs break off trees; progress generally impeded.
|| Moderately high waves of greater length; edges of crests begin to break into spindrift; foam is blown in well-marked streaks along the direction of the wind.
||76 - 87 km/h
|| Slight structural damage occurs -roofing dislodged; larger branches break off.
|| High waves; dense streaks of foam; crests of waves begin to topple, tumble and roll over; spray may affect visibility.
||88 - 102 km/h
|| Seldom experienced inland; trees uprooted; considerable structural damage.
|| Very high waves with long overhanging crests; the resulting foam in great patches is blown in dense white streaks; the surface of the sea takes on a white appearance; the tumbling of the sea becomes heavy with visibility affected.
||103 -117 km/h
|| Very rarely experienced - widespread damage
|| Exceptionally high waves; small and medium sized ships occasionally lost from view behind waves; the sea is completely covered with long white patches of foam; the edges of wave crests are blown into froth.
||118 km/h or more
||64 knots or more
|| The air is filled with foam and spray. Sea completely white with driving spray; visibility very seriously affected