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All thunderstorms are dangerous. Every thunderstorm produces lightning. Although most lightning victims survive, many are left with a variety of long-term, debilitating health consequences. Other dangerous weather associated with thunderstorms include tornadoes, strong winds, hail, flooding, and flash flooding.

Facts About Thunderstorms

  • Thunderstorms can occur singly, in clusters, or in lines.
  • Some of the most severe storms occur when a single thunderstorm affects one location for an extended period of time.
  • Thunderstorms typically produce heavy rain for a brief time, but are known to last for prolonged periods.
  • Warm, humid conditions are highly favorable for thunderstorm development.
  • Severe thunderstorms, which account for about 10% of all thunderstorms, may produce marble-sized or larger hail, straight line 55 mph or higher winds, and/or tornadoes.

Facts About Lightning

  • Lightning is unpredictable, which 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. If you can hear the thunder, you are at risk of being struck by lightning.
  • "Heat lightning" is lightning from a thunderstorm too far away for thunder to be heard.
  • Most lightning deaths and injuries occur when people are caught outdoors in the summer months, during the afternoon and evening.
  • Your chances of being struck by lightning are estimated to be 1 in 600,000 but could be reduced even further by following safety precautions.
  • Lightning strike victims do not pose an electrical threat to other people. Immediately attend to lightning strike victims, as they carry no electrical charge.