Gusts are caused by turbulence due to friction, wind shear and by the sun heating the ground. Gusts are generated when wind blows around surface-based obstacles such as trees or buildings. Taller buildings usually cause the strongest gusts.

What's the difference between wind and wind gust?

A sustained wind is defined as the average wind speed over two minutes. A sudden burst in wind speed is called the wind gusts and typically lasts under 20 seconds.

What causes windspeed?

Air Pressure

At the Earth's surface, wind blows horizontally from high pressure to low pressure areas. The speed is determined by the rate of air pressure change, or gradient, between the two pressure areas. The greater the pressure difference, the faster the winds.