Thunderstorms and lightning: what to do¶
Emergency numbers differ by country. This page uses 911, the number for the United States and Canada. Many other countries use 112, 999, or another number. Find the number for your country.
Lightning can strike miles from the rain, and no place outside is safe during a thunderstorm. This page helps you get inside in time and stay safe until the storm passes.
Do this now¶
- If you hear thunder, go indoors at once. Thunder means you are close enough to be struck.
- Choose a fully enclosed building or a hard topped car with the windows closed.
- Stay inside until 30 minutes after the last thunder you hear.
- Stay off corded phones, and away from plumbing, wired electronics, and windows.
- If someone is struck, call your local emergency number (911 in the United States and Canada, 112 across the European Union, 999 in the United Kingdom) and start first aid.
When thunder roars, go indoors¶
If you can hear thunder, you are within range of lightning. Do not wait for rain. Lightning can strike up to about 16 kilometers (10 miles) from the storm, so it can hit when the sky overhead is clear.
Do not wait to see the storm get closer. Go in at the first sound of thunder, or when you see a flash. The same applies at the beach, on a lake, on a golf course, and on a sports field.
What counts as safe shelter¶
- A fully enclosed building with wiring and plumbing, such as a house, school, or shop
- A hard topped vehicle with the windows up. Do not touch metal parts inside.
Picnic shelters, tents, open sheds, dugouts, and porches are not safe. A tent or convertible car will not protect you.
There is no safe place outside¶
No place outside is safe when thunderstorms are in the area. Trees, open ground, water, and hilltops all carry risk.
Plan outdoor activities around the forecast, and have a place to go. Check the weather before you leave, and know how long it will take to reach shelter. Give yourself time, because the best protection is not being outside.
Wait 30 minutes after the last thunder¶
The storm may seem to have passed, but lightning can still strike. Stay inside until 30 minutes have passed since the last thunder you heard. If you hear more thunder, restart the 30 minute count.
... tip "Use the time" Keep the 30 minutes in mind from the first thunder. If you plan an event, set a time to end it early.
Indoor safety¶
Lightning can travel through wires and pipes.
- Avoid using corded phones, plugged in electronics, and wired headphones
- Stay away from sinks, showers, and baths
- Keep away from windows and doors, and do not lie on concrete floors or lean on concrete walls
- Unplug sensitive equipment before a storm if you can do so before it arrives
Cell phones and cordless phones are safe to use inside.
If you are caught outside¶
If no shelter is within reach, you can only slightly lower your risk. Take these steps while you move toward safety.
- Get away from open fields, hilltops, and ridges
- Stay away from tall, isolated trees, and stay near shorter trees in a forest
- Spread out if you are in a group
- Stay away from water, wet ropes, fences, and metal poles
Do not lie flat on the ground. Crouching with your feet together lowers the contact area, but it does not make you safe. Keep moving toward real shelter as fast as you can.
... warning "Do not shelter under a lone tree" A tall, isolated tree is one of the most dangerous places to stand. Lightning often strikes the tallest object.
If someone is struck¶
Call your local emergency number first. People struck by lightning do not carry an electrical charge, so it is safe to touch them. If they are not breathing, start CPR. Move them to safety only if the storm is still close, and treat any burns.