Lightning AlertsThe storm on the live map
See the strikes of the storm on the horizon, with the newest in red. Intracloud flashes show as well as ground-reaching strikes.
Live lightning map · iOS and Android
See the storm behind heat lightning on a live map.
Heat lightning is lightning from a thunderstorm too far away to hear. See that storm's strikes on the live map, tap one to see how far away it is, and get an alert if lightning comes closer.
Silent flashes. A real storm.
See the storm behind the flashes
How far away it is
Tap a strike to see how far it is from you and in which direction, even when its thunder never reaches you.
An alert if it comes closer
Turn on Lightning alerts and choose your alert distance. Each alert says how close the closest strike is.
Heat lightning guide
What to know about heat lightning
The basics from the US National Weather Service and NOAA, with a link to each source.
- 10 miles (16 km) is about as far as thunder can be heard from a lightning flash, according to the National Weather Service.
- 5 seconds is how long thunder takes to travel about a mile (3 seconds for a kilometer). Count the seconds from the flash to the thunder and divide by 5 to estimate the distance in miles.
What heat lightning is
Heat lightning is not a special kind of lightning. It is the light of a thunderstorm so far away that you cannot hear its thunder. Often you cannot see the lightning bolts either: hills, trees or the curve of the Earth hide them, and you see their light reflected off high clouds.
Sources: NWS: heat lightning
Why you hear no thunder
Thunder can be heard only about 10 miles (16 km) from a flash, but the light of the flash can be seen from much farther away. So a storm beyond that distance looks silent. When thunder starts to follow the flashes, the storm is within about 10 miles.
Sources: NWS: heat lightning · NWS: thunder
Why it is called heat lightning
People see these silent flashes most often in summer, so they were named after the heat. Heat does not make them: they come from an ordinary thunderstorm, even when the sky above you is clear.
Sources: NOAA NSSL · NWS: heat lightning
We checked these sources on October 30, 2026. They are not affiliated with Lightning Alerts and do not endorse the app.
In the app
From silent flashes to the storm on the map
Radar under the strikes, a strike's distance and an alert that opens the map, as they look in the app.
Radar with lightning
Compare rain movement with nearby strikes.
See what struck
Type, polarity, strength, age, distance, and street context.
Open from alerts
Tap an alert to see its closest strike on the live map.
Heat lightning in the app: quick answers
Find the storm behind the flashes, see how far away it is and get an alert if lightning comes closer.
Where is the storm behind the heat lightning?
Open the live map and look in the direction of the flashes. Strikes from the last 10 minutes are red, then orange and pale yellow up to 60 minutes old, so the newest strikes show where the storm is active now. Intracloud flashes show on the map as well as ground-reaching strikes.
How far away is the heat lightning?
Tap a strike on the live map to see how far it is from you and in which direction. Or tap Find and choose Closest to me: the map moves to the nearest detected strike. Flashes without thunder usually come from a storm more than about 10 miles (16 km) away.
Is the storm coming toward me?
Tap Radar to see the rain around the strikes, then start radar playback to see which way it has moved. On the live map, the newest red strikes show where the storm is active now, so you can see whether it is heading your way.
Can I get an alert if the lightning comes closer?
Yes. Turn on Lightning alerts for My Location and one saved place, such as home, and give each its own alert distance. Each alert says how many strikes were detected, how close the closest one is and how recent they are. Tap an alert to see its closest strike on the live map.
Watch distant storms with Lightning Alerts
Live strikes, radar, distances and alerts in one focused lightning app.
Backed by lightning data
Enterprise-grade lightning data places each detected strike on the map, even when its thunder never reaches you.
Open the map without an account
Check the storm behind the flashes without creating an app account.
Free to use
The free version includes the live map, radar, alerts and strike history, with ads. Pro removes ads and replays every storm.