Winds of Beaufort Trivia Quiz

The Beaufort Scale was developed in 1805 by Francis Beaufort, an Anglo-Irish hydrographer. It is an empirical measure that correlates wind speed with observed conditions at sea or on land. It was standardised for use in Royal Navy logbooks in the 1830s and later adapted for non-naval use.

The Beaufort scale is an imprecise and subjective measure based on visual observation of a ship and the sea, with integral wind speeds determined later but not standardised between units.

The term "calm" refers to virtually no airflow (wind speed less than 1 knot).

The surface of the sea is mirror-like with no ripples. It reflects the sky and has a calm and serene appearance.

On land, smoke rises vertically with no horizontal movement, indicating a complete absence of wind.

Light air (1-3 knots)

Sea: Small, short-lived ripples resembling fish scales begin to appear. The surface remains largely calm.

Land: Smoke rises in a straight column, hardly deviating from the vertical, indicating the lightest of breezes.

Light breeze (4-6 knots)

Sea: Waves form with short, frequent crests. The surface takes on a smooth, glassy appearance with small ripples.

Land: The wind becomes noticeable on the surface and smoke drifts slightly, indicating the direction of the wind.

Gentle breeze (7-10 knots)

Sea: Moderate waves with breaking crests and visible foam. The water surface changes with more pronounced wave activity.

Land: Leaves rustling and light flags spreading, showing the increasing influence of the wind.

Moderate breeze (11-16 knots)

Sea: Small waves with breaking crests and fairly frequent whitecaps develop, indicating increasing wind intensity.

Land: Dust begins to rise and small branches show signs of movement.

Fresh breeze (17-21 knots)

Sea: Moderate waves with a pronounced long shape, many whitecaps and some spray. The sea becomes more dynamic and visually active.

Land: Small trees in leaf begin to sway noticeably and the wind picks up.

Strong breeze (22-27 knots)

Sea: Larger waves with more extensive white foam crests, possibly with spray. The sea begins to show a higher degree of turbulence.

Land: Large branches swaying in the wind and wires whistling in the increased force.

High wind or moderate gale (28-33 knots)

The sea: The sea is rough with waves breaking into spindrift and visible foam. Conditions indicate a significant increase in wind.

Land: Whole trees are in motion and walking against the wind creates resistance, showing the increasing strength of the near gale.

Fresh gale (34-40 knots)

Sea: Moderately high, long waves with breaking crests and spindrift. The sea becomes rough and challenging.

Land: Some branches break from trees and the force of the wind is evident in the surroundings.

Strong gale (41-47 knots)

Sea: High waves with dense foam along the wind direction. Conditions become dangerous for small vessels.

Land: Branches break off trees and temporary signs start to move, signalling the increasing impact of the strong gale.

Storm or whole gale (48-55 knots)

Sea: Very high waves with overhanging crests and large patches of foam. The sea transforms into a formidable force with dangerous waves.

Land: Trees break or uproot and considerable structural damage occurs, marking the onset of a severe storm.

Violent storm (56-63 knots)

Sea: Exceptionally high swell with small to medium size vessels likely to be lost in the trough. Conditions are extremely hazardous.

Land: Widespread damage to vegetation occurs, and significant travel disruption is experienced due to the violent storm.

Hurricane (64 knots and above)

Sea: The air is filled with foam and spray, and the sea is completely white with driving spray. A hurricane is a powerful and destructive natural phenomenon.

Land: Very widespread damage is caused, the air is filled with debris and severe disruption to travel occurs, emphasising the extreme impact of a hurricane force wind.

In 1946, forces 13 to 17 were added to the scale, but these were intended for special cases such as tropical cyclones. The extended scale is used mainly in Taiwan and mainland China, areas frequently affected by typhoons. The WMO Manual on Marine Meteorological Services (2012 edition) defines the Beaufort scale internationally only up to force 12, with no recommendation for the use of the extended scale.