Weather Explainers

Weather Words: Wind Gust

Wind gusts are brief bursts of stronger wind caused by atmospheric turbulence and mixing, and they’re often mistaken for sustained winds even though they last only a few seconds.

While winds are part of everyday life, either weak or strong, wind gusts are usually what’s much more memorable. But what’s the difference?

Wind gusts are a brief, sudden increase in wind speed that lasts just a few seconds, standing out from the surrounding, more steady wind. This is different from sustained winds, which represent the average wind speed measured over a longer period of time (typically one or two minutes in the U.S.)

Because gusts are short-lived but often stronger, they’re the wind speeds people tend to notice most, especially when tree branches come tumbling down or loose objects are suddenly blown over.

This image shows damage after a storm with at least 50 mph wind gusts.
(NOAA)

It’s common for people to confuse gusts with sustained winds, particularly during storms. Forecasts might call for sustained winds of 25 mph with gusts to 45 mph, but it’s the higher gust number that often sticks in people’s minds. Gusts don’t mean the wind is blowing at that speed continuously. Instead, they’re momentary bursts that can cause significant damage, especially when combined with already weakened structures or limbs.

So what causes gusts? Gusts form because the atmosphere is rarely smooth or uniform. Turbulence, changes in wind direction and speed with height, and pockets of faster-moving air mixing down to the surface all play a role. During storms or behind strong cold fronts, powerful winds just a few thousand feet above the ground can be dragged downward by heavier air or precipitation, briefly boosting surface winds. That’s why gusts are often strongest during showers, thunderstorms or when a sharp pressure gradient is in place.

Jennifer Gray is a weather and climate writer for weather.com. She has been covering some of the world's biggest weather and climate stories for the last two decades.