Lightning Facts

 

Back to Hazards Directory 

 

Central Florida is the most lightning prone area in the United States with about 90 thunderstorm days a year. Because of this, Florida has more lightning deaths than any other state. In fact, lightning kills more people in Florida than all other weather hazards combined. In the Florida peninsula thunderstorm season has two general periods. The summer months, from early May to early October are known as the wet season. Conversely, October through May is known as the dry season. Historically, the most dangerous months are June, July and August. This is due to an abundance of moisture, atmospheric instability and storm triggering sea breezes. Moisture is almost always available in the summer because Florida is a peninsula with the Gulf of Mexico to the west and the warm Atlantic Gulfstream to the east. Instability is a function of surface heat and cool air aloft, something present for most of the summer season. Finally, a trigger is needed to get thunderstorms going. This is provided daily in the form of the sea breeze that forms on the Atlantic and Gulf coasts. As a sea breeze forms, it typically moves inland (from the Atlantic or Gulf of Mexico) and dramatically aids thunderstorm formation.Surface winds also play a big part in determining which areas get the most lightning and at what time they get it. With westerly morning winds across the peninsula, afternoon thunderstorms tend to pile up on the east coast. If the morning winds are from the east, afternoon thunderstorms will cluster on the west coast.

 

Lightning seeks the path of least resistance on its way to and through the ground. The human body is an extremely good conductor because of its large water content. Metal is a better conductor than most objects so lightning can travel easily through metal objects such as fences or railroad tracks, which can conduct electricity for long distances. The fact is, if you live in Florida, you are at risk. So, please learn lightning safety rules. It could save your life or the life of someone you love.

 

Lightning Precautions
  • Avoid open high ground and isolated large trees.
  • Avoid water (swimming pools, lakes and rivers), beaches and boats.
  • Seek shelter inside a building or an automobile, but not a convertible or a golf cart.
  • Stay away from doors, windows, and metal objects such as pipes or faucets.
  • Stay off the telephone and away from electrical devices.
  • Monitor NOAA Weather Radio.

More Lightning Facts
  • Air in a lightning stroke is heated to 50,000 degrees Fahrenheit. This rapid heating of the air produces the shock wave that results in thunder.
  • A ground stroke can produce somewhere between 100 million to one billion volts of electricity.
  • Average peak current in a cloud-to-ground lightning stroke is 100,000 Amperes.
  • Estimated diameter of a lightning channel is around one inch.
  • The length of an average cloud-to-ground lightning channel can range from two to ten miles.
  • You can tell how far away lightning is by counting the seconds between seeing the lightning flash and hearing thunder. For every five seconds you count, lightning is one mile away.
  • National Lightning Detection Network data in recent years was used to estimate that...
    • One death occurred for every 345,000 flashes
    • One injury occurred for every 114,000 flashes
  • Overall, a rate of 7.7 casualties per million people, per 100 million flashes, was found for the entire United States.
A frequently asked question is, "How likely am I to be struck by lightning?" This is a seemingly simple question, but there is no single answer that fits everyone. The average annual per capita strike rate in the United States is around 1 in 600,000. However, this does not mean your odds of being struck are 1 in 600,000.

 

The odds of being struck vary from person to person, and are determined by a number of different factors. Among the most significant are:
  • Geographical location and climatology
  • Daily and annual climatology
  • Personal lifestyle/hobbies

Average number of thunderstorms occurring worldwide at any given moment--2000
Average number of lightning strikes worldwide every second--100
Average number of lightning strikes worldwide per day--8.6 Million
Average number of lightning strikes in the USA per year--20 Million
VOLTS in a lightning flash--between 100 Million and one Billion
AMPS in a lighting flash--between 10,000 and 200,000

How far away is lightning from you?
1...When you see the FLASH
2...Count the number of seconds to the BANG of thunder
3...Divide this number by 5,
4...And this gives you the MILES the lighting is away from you
It is recommended if the thunder arrives within 30 seconds or less from your location, you should seek shelter!

Example:
If it takes 15 seconds between the time you see a lightning flash and hear the rumble of thunder, then the lightning flash is 3 miles from your location (too close!!)

30-30 Rule--Determine the threat of lightning in your area.
30 Seconds:
Count the seconds between seeing lightning and hearing thunder. If this time is less than 30 seconds, lightning is still a potential threat. Seek shelter immediately.
30 Minutes:
After the last lightning flash, wait 30 minutes before leaving shelter. Half of all lightning deaths occur after the storm passes. Stay in a safe area until you are sure the threat has passed.