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What are derechos?

03.41
22. juni 2025

Stay severe weather-aware
What are derechos?

A tree fell across vehicles at a home in West Des Moines, Iowa, after a severe thunderstormA tree fell across vehicles at a home in West Des Moines, Iowa, after a severe thunderstorm moved across Iowa on Monday Aug. 10, 2020, downing trees, power lines and damaging buildings. - © picture alliance / ASSOCIATED PRESS | David Pitt

Derechos are a part of the severe weather that slides through the U.S. every summer, with 30 percent happening in the winter, they can be very dangerous.

Derechos are widespread, long-lived, straight-line wind storms associated with a fast-moving group of thunderstorms. These storms are hazardous since they can be much stronger than your average thunderstorm. Derechos can produce hurricane-force winds, huge hail, tornadoes, and heavy flooding rains.

They can cause death and damage:

According to the National Weather Service, the costliest thunderstorm in history was a derecho event resulting in $11 billion in damages across the Midwest on Monday, August 10, 2020.

August 2020 Derecho producing hurricane force wind in Palo, Iowa.

Derecho formation is most favorable in a warm & humid environment of moderately strong instability and strong vertical wind shear—conditions present most likely between April and August. However, with the right ingredients, 30 percent of them can happen during the colder months.

Geographically, derechos are most common across the Midwest and from Oklahoma across the Ohio Valley; however, occasionally, they can occur outside of this area. One such event was the June 6, 2020, derecho, which affected Nevada, Utah, and Wyoming. Most recently on May 16, 2024, a derecho killed eight people in the Greater Houston area as wind gusts reached 100 mph in Downtown Houston, causing many windows to be broken in high-rise apartments and power outages.

If you want to stay informed of incoming severe thunderstorms, including derechos, make sure to activate storm alerts on your Weather & Radar app. First, go to the Settings Menu by tapping on the top left icon on your home screen. Then, head down to Weather Alerts and switch the toggle button to activate.

Federico Di Catarina
Weather & Radar USA editorial team
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