ASK THE METEOROLOGIST
“How much fast is lightning than sound?”
John from Mr. Ward’s 6th grade class, St. Mary’s School in Medford
The short answer is that lightning is MUCH faster than sound. But the lightning bolt itself travels slower than the speed of light, which is the lightning bolt you see from a distance. The speed of light is roughly over 670,000,000 miles per hour! Sound travels at about 760 miles per hours, which is still fast, but compared to the speed of light, seems like a snail’s pace. That why you see the lightning almost instantly, but it takes a while for you to hear the thunder. As mentioned previously, the actual lightning bolt travels at about 1/3 the speed of light.
So, with that said, the speed of lightning is about 880,000 times faster than that of sound, or the thunder clap. This comes in handy with the old rule for counting the miles between you and the lightning strike. After you see the lightning, start counting until you head the thunder. For every five seconds you count, that equals one mile of distance. For example, if you count 25 seconds before the thunder, that means the lightning strike was about 5 miles away.
Great question, John!
Chief Meteorologist Kate McKenna