Severe Weather 101 – Lightning and lightning safety
Friday, April 16th, 2010 5:45pm MDT
This is NOT the time to be outside. (michaeljames / FLICKR)
Of all the weather types associated with thunderstorms – hail, tornadoes, floods, etc – lightning is usually the most dangerous. In the United States there are an estimated 25 million cloud to ground lightning flashes each year and each one is a potential threat to life and property. During the past 10 years there has been an annual average of 44 lightning fatalities in the United States.
Colorado is ranked # 2 in lightning related deaths (1997 – 2006) so the danger this presents to life and property is very significant for us. It is interesting to note though that Colorado ranks only 31st in the number of cloud to ground strikes over that same period. We have fewer strikes and yet more deaths. This highlights the fact that, quite frankly, folks here in Colorado are not aware of the dangers lightning presents and they do not take proper steps to protect themselves. One of the great things about Colorado are the outdoor activities we all enjoy, but there comes a time when we need to head indoors.

Colorado ranks # 2 in lightning related deaths - think about that before you head outside when you see lightning! (NOAA)
Three years ago in 2006, Colorado had the sad distinction of having more lightning fatalities than anywhere else – six of them – as well as 15 injuries from lightning. In 2007 we improved with two fatalities and six people who survived a strike. Last year, in 2008, four Coloradoans were killed by lightning and seven injured. On average, Colorado suffers three deaths and 13 injuries.
As thunderstorm season approaches, it is time to educate ourselves on the dangers of lightning.
Lightning Fast Facts
- If you can see it or hear it, lightning can hit you. Find shelter now.
- The primary rule for lightning safety: When Thunder Roars, Go Indoors!
- Lightning is the number two weather killer in the United States (behind floods), killing more than hurricanes and tornadoes combined.
- Lightning kills about 60 people in the U.S. each year and inflicts severe life-long debilitating injuries on at least a 1,000 people a year.
- Every 5 seconds between flash and boom is a mile’s distance from you.
- Under ideal conditions, lightning’s thunder can be heard 12 miles away.
- Lightning is really no wider than a few inches.
- “Bolts from the Blue” – These lightning flashes have been documented to travel more than 25 miles away from the thunderstorm cloud. Clear skies above you are no indication of how dangerous a nearby storm is!
- The air within a lightning strike can reach 50,000 degrees Fahrenheit.
- Lightning can heat its path five times hotter than the surface of the sun.
- One ground lightning stroke can generate between 100 million and 1 billion volts of electricity.
Lightning Safety Facts
- The “30-30 Rule” offers easy to follow lightning safety guidance. When you see lightning, count the time until you hear thunder. If that time is 30 seconds or less, the thunderstorm is close enough to be dangerous. Seek shelter. If you can’t see the lightning, just hearing the thunder is a good back-up rule. Wait at least 30 minutes after the lightning flash before leaving shelter.
- No place outside is safe during a thunderstorm!
- A house, or other fully enclosed building with wiring and plumbing offers your best protection against lightning. Once inside stay off of corded telephones, computers and other electrical appliances and stay away from sinks, showers, indoor pools and other plumbing. Don’t watch lightning from windows or doorways. Inner rooms are safer.
- A car with a metal roof and sides is your second best protection against lightning. As in a house, don’t touch any conducting paths leading outside. It is the metal shell that protects you, not the rubber tires.
- Lightning causes about $5 billion of economic impact in the U.S. each year!

Lightning flashes over downtown Denver. (Wikipedia)
What are the odds?
Here are some scary statistics to think about.
The odds of an individual being a lightning casualty (injured) in a year in the U.S. is about 280,000-to-1. If you’re an average person, in an average location, with average outside activities, and average lightning safety behavior. That’s about 3,000-to-one over your lifetime, with about 300-to-one odds of being seriously affected by a family member or friend being a lightning survivor.
The odds of an individual being killed by lightning each year in the U.S. is about 3 million-to-1, if you’re an average person, in an average location, with average outside activities, and average lightning safety behavior. That’s about 35,000-to-one over a life time, and about 3,000-to-one of being seriously affected by a family member or friend being killed by lightning.
Think about that. Three thousand to one odds that you yourself will be injured by lightning over your lifetime. That’s not very good odds at all. The next time you are outside and you see the telltale flash or hear the rumble, keep this in mind and please take appropriate precautions – the odds are against you if you don’t!
Colorado Lightning Injury Data – 1959-1995
|
LOCATION
|
NUMBER OF INJURIES
|
PERCENT
|
| OPEN FIELDS, BALL PARKS, AND OPEN SPACES |
130
|
40%
|
| UNDER TREES |
32
|
10%
|
| BOATING, FISHING, AND WATER RELATED |
20
|
6%
|
| NEAR TRACTORS OR HEAVY ROAD EQUIPMENT |
7
|
2%
|
| GOLF COURSES |
18
|
5%
|
| AT TELEPHONES |
6
|
2%
|
| VARIOUS UNKNOWN LOCATIONS |
115
|
35%
|
Colorado Lightning Deaths – 1959-1995
|
LOCATION
|
NUMBER OF DEATHS
|
PERCENT
|
| OPEN FIELDS, BALL PARKS, AND OPEN SPACES |
48
|
48%
|
| UNDER TREES |
19
|
19%
|
| BOATING, FISHING, AND WATER RELATED |
5
|
5%
|
| NEAR TRACTORS OR HEAVY ROAD EQUIPMENT |
3
|
3%
|
| GOLF COURSES |
7
|
7%
|
| AT TELEPHONES |
0
|
0%
|
| VARIOUS UNKNOWN LOCATIONS |
17
|
17%
|
Think about it!
This is part five of a five part series on Colorado’s severe weather.
Tags: lightning, lightning safety

