Thunderstorms and Lightning


All thunderstorms are dangerous. Every thunderstorm produces lightning. Lightning is one of the top three storm-related killers in the United States.

Facts About Thunderstorms

  • They may occur individually, in clusters, or in lines.
  • Some of the most severe occur when a single thunderstorm affects one location for an extended time.
  • Thunderstorms typically produce heavy rain for a brief period, anywhere from 30 minutes to an hour.
  • Warm, humid conditions are highly favorable for thunderstorm development.
  • About 10 percent of thunderstorms are classified as severe—one that produces hail at least three-quarters of an inch in diameter, has winds of 58 miles per hour or higher, or produces a tornado.

Facts About Lightning

  • Lightning’s unpredictability increases the risk to individuals and property.
  • Lightning often strikes outside of heavy rain and may occur as far as 10 miles away from any rainfall.
  • “Heat lightning” is actually lightning from a thunderstorm too far away for thunder to be heard. However, the storm may be moving in your direction!
  • Most lightning deaths and injuries occur when people are caught outdoors in the summer months during the afternoon and evening.
  • Lightning strike victims carry no electrical charge and should be attended to immediately.

Specific information on what to do Before, During and After a Thunderstorm and Lightning Strike can be found at: www.ready.gov/thunderstorms-lightning.