Also, stay out of water and get off small boats. If your hair stands on end, your skin starts to tingle, or you hear clicking sounds, lightning maybe about to strike. Get down on your hands and knees and keep your head tucked in. DO NOT lay flat on the ground. That can give lightning a better chance of striking you.
Thunder is created when lightning heats up the air around it and causes it to expand rapidly.
Because light travels very fast, you see lightning as it happens. Sound on the other hand travels much slower than light and therefore takes much longer to get to you. So, you hear the thunder after you see the lightning. It takes thunder 5 seconds to travel one mile. You can use this to tell how far away a lightning strike was.