Lightning Safety Awareness Week – “When Thunder Roars, Go Indoors!”

Summer is the season to be outside. Warm weather compels us to run, swim, hike and ride, and the long hours of sunlight provide ample time to enjoy this most active of seasons. Summer is also prime time for thunderstorms, which produce lightning, among other potentially dangerous hazards.  June 23-29, 2013 is Lightning Safety Awareness Week! Lightning occurs in ALL thunderstorms and it is estimated that over 100,000 thunderstorms occur each year in the United States. (View state-by-state data on average annual number of thunderstorm days.)

Viewer Tip: In 2012, lightning accounted for 28 deaths in the U.S., down from the 30-year average of 55. That number can be reduced even more by knowing how to avoid lightning and what to do if you are stuck outside during a thunderstorm. These helpful hints will help you stay safe:

  • Pay attention to the forecast. When thunderstorm development is expected, meteorologists often issue a statement early in the day about when the chance for thunderstorms is highest. If your area has a high potential for thunderstorms, make plans to be inside during that time. Lightning can strike up to 10 miles away from a thunderstorm. If a severe thunderstorm watch or warning has been issued for your area, take cover immediately and wait for at least 30 minutes after the storm has passed to head back outside.
  • If you must be outdoors, avoid activities that increase the risk of being struck by lightning, such as mountaintop hiking, swimming at beaches and outdoor pools, golfing and playing other sports in open fields.
  • If you are caught outside during a thunderstorm and cannot reach a safe, indoor location, avoid open fields and the tops of hills or ridge tops. Stay away from tall, isolated trees and other tall objects. If you’re in a forest, stay near a lower stand of trees. Stay away from water, wet items and metal objects like fences and poles.
  • Learn more about lightning development, safety, and science at NOAA’s Lightning Safety webpage.

Did you know?

  • Lightning impacts the environment: Every year, lightning causes forest, grass and house fires across the United States. According to the National Fire Protection Association, lightning caused an average of 24,600 fires resulting in 407 million dollars in damages annually from 2004-2008. Wildfires started by lightning burn on average 5.5 million acres each year.
  • The environment impacts thunderstorm development: Many big cities experience the urban heat island effect. Urban heat islands form when buildings, roads and other infrastructure absorb heat, making cities warmer than surrounding rural areas. In Atlanta, studies have shown that excess heat from the urban heat island plays a role in producing increased rainfall and thunderstorms over the city. Similarly, Houston (dubbed the “Lightning Capital of Texas”) received more lightning than surrounding less-developed areas over a 12-year period. Data analysis suggests that Houston’s urban heat island effect causes clouds and thunderstorms. Air pollution in Houston may also play a role – small particles emitted by cars and power plants join up with other aerosols to form nuclei on which water condenses to form clouds.

Thanks to Mount Washington Observatory for providing some of these lightning facts.

Image courtesy of NOAA.

(Sources: NOAA, “Lightning Safety: When Thunder Roars, Go Indoors!” http://www.lightningsafety.noaa.gov/; EPA, “Heat Island Effect,” http://www.epa.gov/hiri/; NASA, “Welcome to the Thunder Dome Atlanta’s Urban Heat Island Alters Weather Patterns,” http://science1.nasa.gov/science-news/science-at-nasa/1999/essd26apr99_1/; NASA, “Houston Called ‘Lightning Capital of Texas,’” http://earthobservatory.nasa.gov/Newsroom/view.php?id=22561; NOAA, “Thunderstorms, Tornadoes, Lightning…Nature’s Most Violent Storms,” http://www.nws.noaa.gov/os/severeweather/resources/ttl6-10.pdf; NWS, “Natural Hazard Statistics,” http://www.nws.noaa.gov/om/hazstats.shtml; National Fire Protection Association, “Lightning Fires and Lightning Strikes,” http://www.nfpa.org/assets/files/PDF/OS.lightning.pdf; NOAA, “Number of Cloud-to-Ground Flashes by State from 1997-2011,” http://www.lightningsafety.noaa.gov/stats/Table-Flashes_by_State_1997-2011.pdf)


State-by-State Data: Average Number of Thunderstorm Days Per Year

  • Alabama sees an average of 50 thunderstorm days per year, and can see up to 80 days per year in southern parts of the state
  • Alaska sees an average of five thunderstorm days per year.
  • Arizona sees an average of five to 50 thunderstorm days per year.
  • Arkansas sees an average of 50 thunderstorm days per year.
  • California sees an average of five to 10 thunderstorm days per year.
  • Colorado sees an average of 30 to 60 thunderstorm days per year.
  • Connecticut sees an average of 10 thunderstorm days per year.
  • Delaware sees an average of 20 thunderstorm days per year.
  • District of Columbia sees an average of 20 thunderstorm days per year.
  • Florida sees an average of 60 to 100 thunderstorm days per year.
  • Georgia sees an average of 60 thunderstorm days per year.
  • Hawaii sees an average of six to 10 thunderstorm days per year.
  • Idaho sees an average of 10 to 40 thunderstorm days per year.
  • Illinois sees an average of 30 to 50 thunderstorm days per year.
  • Indiana sees an average of 40 to 50 thunderstorm days per year.
  • Iowa sees an average of 40 to 50 thunderstorm days per year.
  • Kansas sees an average of 50 thunderstorm days per year.
  • Kentucky sees an average of 40 to 50 thunderstorm days per year.
  • Louisiana sees an average of 50 to 70 thunderstorm days per year.
  • Maine sees an average of 10 to 20 thunderstorm days per year.
  • Maryland sees an average of 20 to 40 thunderstorm days per year.
  • Massachusetts sees an average of 10 to 20 thunderstorm days per year.
  • Michigan sees an average of 20 to 40 thunderstorm days per year.
  • Minnesota sees an average of 30 to 40 thunderstorm days per year.
  • Mississippi sees an average of 50 to 70 thunderstorm days per year.
  • Missouri sees an average of 50 thunderstorm days per year.
  • Montana sees an average of 20 to 40 thunderstorm days per year.
  • Nebraska sees an average of 40 to 50 thunderstorm days per year.
  • Nevada sees an average of 10 to 30 thunderstorm days per year.
  • New Hampshire sees an average of 10 to 20 thunderstorm days per year.
  • New Jersey sees an average of 20 to 30 thunderstorm days per year.
  • New Mexico sees an average of 40 to 70 thunderstorm days per year.
  • New York sees an average of 20 to 30 thunderstorm days per year.
  • North Carolina sees an average of 40 to 50 thunderstorm days per year.
  • North Dakota sees an average of 20 to 30 thunderstorm days per year.
  • Ohio sees an average of 30 to 40 thunderstorm days per year.
  • Oklahoma sees an average of 40 to 50 thunderstorm days per year.
  • Oregon sees an average of five to 20 thunderstorm days per year.
  • Pennsylvania sees an average of 20 to 40 thunderstorm days per year.
  • Rhode Island sees an average of 10 thunderstorm days per year.
  • South Carolina sees an average of 40 to 50 thunderstorm days per year.
  • South Dakota sees an average of 30 to 40 thunderstorm days per year.
  • Tennessee sees an average of 40 to 50 thunderstorm days per year.
  • Texas sees an average of 20 to 50 thunderstorm days per year.
  • Utah sees an average of 30 to 40 thunderstorm days per year.
  • Vermont sees an average of 20 thunderstorm days per year.
  • Virginia sees an average of 20 to 50 thunderstorm days per year.
  • Washington sees an average of five to 20 thunderstorm days per year.
  • West Virginia sees an average of 30 to 40 thunderstorm days per year.
  • Wisconsin sees an average of 30 to 40 thunderstorm days per year.
  • Wyoming sees an average of 30 to 50 thunderstorm days per year.


Alabama sees an average of 50 thunderstorm days per year, and can see up to 80 days per year in southern parts of the state
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