How do I calculate how far away lightning is?

Count the seconds between seeing the lightning flash and hearing the thunder, then multiply by the speed of sound (about 343 metres per second). As a quick rule, divide the seconds by 3 for the distance in kilometres, or by 5 for miles. This tool does the timing and the maths for you with a built-in stopwatch.

Why does counting seconds work for lightning distance?

Light travels about a million times faster than sound, so you see the flash effectively the instant lightning strikes. The thunder, travelling at roughly 343 m/s, then takes about 3 seconds to reach you for every kilometre, or 5 seconds for every mile. Timing that delay gives a good estimate of the strike distance.

What is the 30-30 lightning safety rule?

If you hear thunder within 30 seconds of seeing the flash, the lightning is close enough (about 10 km / 6 miles) to be dangerous and you should move indoors. After the storm, wait at least 30 minutes after the last thunder before returning outside, because lightning can strike well ahead of and behind the visible rain.

How accurate is the real-time lightning map?

The map's lightning data comes from Blitzortung.org's global network of volunteer-operated detection stations. While highly accurate in well-covered areas like Europe and North America, coverage may vary in remote regions. Data is typically updated within seconds of actual strikes.

What do the different colors on the map mean?

Lightning strikes are color-coded by age. White and yellow indicate the most recent strikes (within the last few minutes), while orange, red, and dark red represent progressively older strikes up to 20 minutes in the past.

Can I use this map to protect my property from lightning?

This map is for entertainment and educational purposes only. It should NOT be used as a safety tool to protect people, property, or equipment. Always rely on official weather services and lightning safety guidelines for protection decisions.

Will my display settings be saved for next time?

Yes! Your preferences including selected region, display settings, and sound options are automatically saved in your browser's local storage. They'll be restored the next time you visit.

Free Online Lightning Distance Calculator & Strike Map (No Signup)

How Far Away Is the Lightning?

Tap Flash the instant you see lightning, then tap Thunder the moment you hear it. Sound travels about 343 m/s, so the gap reveals the distance — roughly 3 seconds per km, 5 seconds per mile.

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ReadyTime a flash-to-thunder gap to estimate the distance and check the 30-30 safety rule.

Strike History

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Live Global Strike Map

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About This Map

What You're Seeing

This map displays real-time lightning strikes detected by the Blitzortung.org network—a community of volunteers operating lightning detection stations worldwide. Watch as strikes appear in real-time, with colors indicating how recently each strike occurred.

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The Physics (Flash-to-Bang)

You see lightning the instant it strikes, but its thunder travels at the speed of sound — about 343 metres per second at 20°C. Distance equals that speed multiplied by the delay you time, which works out to roughly 1 km every 3 seconds, or 1 mile every 5 seconds.

The 30-30 Safety Rule

If thunder follows the flash by 30 seconds or less, the storm is within about 10 km (6 miles) — close enough to strike, so head indoors. Then wait at least 30 minutes after the last thunder before going back out. Your timed strikes and a storm approaching/receding trend are saved in your browser.

Detector Network

The live map is powered by Blitzortung.org, a community of over 2,000 detection stations in 80+ countries. Coverage is strongest in Europe and North America. Each detection requires multiple stations to triangulate a strike's location, ensuring accurate positioning.