Weather at Home: How to calculate how far you are from lightning


DENVER (KDVR) — Today’s Weather at Home activity is a lesson on how to calculate how far away you are from lightning. As storm season gets closer, this will be a good reminder for kids (and adults) on how to stay safe from lightning.

All you’ll need to try this out is a stopwatch, calculator, a pen and paper.

The next time you see a thunderstorm, all you need to do it start the stopwatch after you see a flash of lightning and stop it once you hear the sound of thunder.

Make sure you and your kids are staying inside to do this so that you are safe from the storm.

Once you have the number of seconds that passed between the flash of lightning and hearing the sound of thunder, you divide that number by 5 and that will equal the amount of miles that you are from the lightning.

Let’s say that the amount of seconds between lightning and thunder was 5 seconds, once you divide by 5, that equals 1, meaning that the lightning is about 1 mile away from you. If there are 10 seconds between the lightning and thunder, the storm is about 2 miles away.

In a storm, lightning and thunder happen around the same time. Lightning is so hot, it rapidly causes the atmosphere to heat up and expand and that is what causes thunder. Light travels much faster than sound, so that is why we see the flash first and then hear the thunder several seconds later. That is why we divide the number of seconds between lightning and thunder by 5.

Lightning safety tips:

The safest places to be when there is lightning is inside a building or inside a car with a metal roof and all of the windows rolled up. The saying “When Thunder Roars, Head Indoors” is a good rule of thumb because anytime that you can hear thunder, it means that lightning is close enough to strike.

Sometimes when storms are farther away than 10 miles, we can’t hear any thunder. This is because sound dissipates when it travels outward. This is what we call heat lightning.

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