When you notice darkening clouds in the sky accompanied with sudden wind shifts, a thunderstorm may be approaching. If local authorities have issued a watch or warning, heed their instructions on what to do and whether you need to take cover.

Outdoor Safety

When thunderstorms are likely, postpone outdoor activities and avoid going outdoors if at all possible. If you are caught outdoors in a thunderstorm, follow these tips to stay safe until the storm passes:

  • If you are in an open area, find a low place such as a ravine or valley. Be alert for flash floods.
  • If you are in a forested area, find shelter in a low area under a thick growth of small trees, if possible.
  • If you are on open water, get to land immediately and seek shelter.
  • If you are in a car, keep the windows closed.
  • If you are outdoors and feel your hair stand on end (an indication that lightning is about to strike), do not lie flat on the ground, as your fully-extended body will provide a larger surface to conduct electricity. Instead, squat low to the ground and place your hands over your ears and your head between your knees. The goal is to make you the smallest target possible and minimize contact with the ground.
  • Stay away from anything made of metal ”“ bicycles, golf clubs, golf carts, motorcycles, tractors and farm equipment.
  • Stay away from natural lightning rods, such as a tall tree in an open field, and avoid hilltops, the beach or boats on open water.


In addition to heavy rains and the threat of lightning, hail can pose a big danger during a thunderstorm. Hail can be as small as the size of a pea, or as large as a softball. Because it falls from the sky, it can reach extremely high speeds as it barrels toward earth and damage anything in its path: cars, windows and especially plants and agricultural crops.

If you see or hear hail hitting the ground during a thunderstorm, take it as an unmistakable sign that you need to remain inside if you’re already indoors or find shelter quickly if you’re outdoors. A few facts about hail:

  • Though hail rarely causes fatalities, more than 20 people are injured by falling hail each year in the United States.
  • Hail size is measured by National Weather Service Doppler radar, which estimates the size of hail according to its diameter. Sizes range from pea-size (1/4 inch), to quarter size (1 inch) and golf-ball size (1 3/4 inches), all the way up to softball-size (4 1/2 inches). Hail larger than quarter-size (1 inch in diameter) is considered severe.
  • The larger the thunderstorm, the greater the chance for larger hail to be produced ”“ so stay alert if you notice especially large thunderstorm clouds developing in your area.
  • The majority of hail damage each year occurs to agricultural crops, as the area of the U.S. most at risk for large hail lies in the western Great Plains states. This 625-square-mile-wide area sees an average of 7 to 9 days with hail each year.

Indoor Safety

If you’re indoors when thunderstorms are imminent or occurring in your area, stay inside and follow these tips to secure your home and property:

  • Shutter windows and secure outside doors. Also, close your window blinds, shades or curtains, and keep a safe distance from them.
  • Secure any objects outside your home that could blow away or cause damage.
  • Stay away from faucets, sinks, showers, and bathtubs. Plumbing and bathroom fixtures can conduct electricity.
  • Avoid using a corded (landline) telephone during a thunderstorm, for the same reason. Cellular/mobile phones are safe to use.
  • Unplug electrical appliances such as televisions, computers and corded phones, and turn off air conditioners. Power surges that occur as the result of lightning can cause severe damage to plugged-in electronics and appliances.
  • Keep pets inside, on a leash or in a crate or carrier.
  • Make sure you have a battery-powered radio or NOAA Weather Radio so you can receive weather alerts and storm updates if you lose power.

Know Your Terms

  • severe thunderstorm watch is issued when conditions are conducive to the development of severe thunderstorms in and around the watch area and indicates when a severe thunderstorm is likely to occur.
  • severe thunderstorm warning is issued when a severe thunderstorm has been observed by spotters or indicated on radar. Warnings indicate that a severe thunderstorm is occurring or imminent in the warning area, and is a danger to life and property in the path of the storm.