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Lightning Safety Program
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How Far Away Is Lightning From Me?

To estimate the distance between you and a lightning flash, use the "Flash to Bang" method: If you observe lightning, count the number of seconds until you hear thunder. Divide the number of seconds by five to get the distance in miles.

Example: If you see lightning and it takes 10 seconds before you hear the thunder, then the lightning is 2 miles away from you (10 divided by 5 = 2 miles).

If Thunder is heard The Lightning is...
5 seconds after a Flash 1 mile away
10 seconds after a Flash 2 miles away
15 seconds after a Flash 3 miles away
20 seconds after a Flash 4 miles away
25 seconds after a Flash 5 miles away
30 seconds after a Flash 6 miles away
35 seconds after a Flash 7 miles away
40 seconds after a Flash 8 miles away

Since lightning can strike up to 10 miles from a storm, you should seek safe shelter as soon as you hear thunder or see lightning. Get to a safe location if the time between the lightning flash and the rumble of thunder is 30 seconds or less.

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