Each year, lightning strikes the United States approximately 25 million times, mostly during the summer. It claims the lives of about 20 people annually, according to the weather service. The threat of lightning becomes more pronounced as thunderstorms draw nearer, peaking when the storm is directly overhead and gradually waning as it moves away.

The warning is in effect until 6 p.m. Lightning strikes the United States about 25 million times a year. Most of the strikes occur in the summer, killing 20 people each year, according to the NWS. Chance of lightning increases as a thunderstorm approaches and peaks when the storm is overhead. It diminishes as the storm moves away.