One of the main concerns, especially in a severe thunderstorm, is lightning, which is very dangerous.
A handy way to figure out how far lightning is from you is called the five second rule. Light travels faster than sound so when you see lightning in the distance, start counting! For every five second you count until you hear thunder, that equals 1 mile away from where the lightning occurred.
So if there was 15 seconds from when you saw the lightning to when you heard the thunder, that means the storm was about 3 miles away from you. As the time gets shorter, the distance gets lower and that means a storm is getting closer to you.
Lightning can strike 15 miles away from a storm. It doesn’t need to be raining over you to get struck by lightning and if you can hear thunder, you are close enough to a storm to get struck by lightning.
As a fun way to remember: “When thunder roars, go indoors.”