Wind gusts are abrupt but transient increases in wind speed. They are frequently made when the wind brushes against structures, trees, or other obstructions, causing the wind to slow down and then accelerate back up due to friction.
Gusts can form when air flows from high to low pressure as a result of chaotic variations in atmospheric pressure induced by larger-scale oscillations in wind direction or speed (known as wind shear). The air above a Sun-warmed surface rises and warms, causing gusts as colder, denser air rushes below to take its place.
The likelihood of a gust increases with average wind speed. However, depending on the local topography, towns and cities tend to produce more gusts due to friction and sun heating. Urban locations are consequently likely to see substantially higher gusts than open landscapes when considering the same typical wind speed.