Hide Under Trees in Storms (Lightning Danger)
Do not shelter beneath a tree during a thunderstorm. Lightning can strike a tree, travel through its trunk or the ground, and injure people nearby; falling branches are another danger. At the first thunder, head to a substantial enclosed building or a hard-topped, fully enclosed vehicle. Stay there until at least 30 minutes after the last thunder.
A storm does not have to be overhead for lightning to be a threat. The National Weather Service (NWS) warns that lightning can strike more than 10 miles from the part of a storm where rain is falling. If you hear thunder, you are close enough to be at risk.
That makes a tree canopy a poor shelter, even when it feels like the quickest way to get out of the rain. A tree offers no dependable protection from a strike or from electrical current moving through the ground. I use a simple rule in safety planning: leave exposed areas early, choose real shelter, and do not treat any outdoor position as safe.
Storm Monitoring and Shelter Planning
Monitoring means noticing signs of a storm early enough to leave outdoor areas before conditions worsen. Thunder is a clear warning to act; you do not need to see lightning first. A route to proper shelter, planned in advance, can help you avoid the risky last-minute choice to stop beneath a tree.
Before an outdoor activity, identify the nearest substantial, enclosed building and a hard-topped vehicle that can serve as shelter. A picnic shelter, gazebo, tent, or other open-sided structure is not an equivalent substitute. Check weather forecasts and alerts, but keep listening for thunder once you are outside.
At the first thunder or lightning:
- Stop outdoor activity and head promptly to a substantial enclosed building or hard-topped, fully enclosed vehicle.
- Do not detour toward trees, open-sided shelters, or water.
- Help children and anyone who may need extra time move toward shelter early.
- If you are responsible for a group, make the shelter plan clear before people spread out.
The practical detail that matters is time. Do not wait for heavy rain, a nearby strike, or a change in wind to begin moving. Lightning may occur ahead of the rain, and a tree that looks like a convenient waypoint can increase your exposure rather than reduce it.
Planning scenario: A family walking in a park hears thunder while still some distance from the car. The safer choice is to head directly to the hard-topped vehicle, rather than pause under a large tree or in an open picnic shelter. This is a planning example, not a report of a specific event.
Safe Shelter Choices and Tree Clearance
A safe shelter choice is one that provides meaningful protection from lightning, rather than just cover from rain. The NWS identifies a substantial, fully enclosed building or a hard-topped, fully enclosed vehicle as preferred options. Trees and open-sided structures do not meet that standard.
| Location | Use it as lightning shelter? | Key point |
|---|---|---|
| Substantial, fully enclosed building | Yes | Go inside and stay there while thunder remains a concern. |
| Hard-topped, fully enclosed vehicle | Yes | Close the windows and remain inside. |
| Open-sided pavilion or picnic shelter | No | A roof alone does not make it equivalent to an enclosed building. |
| Beneath or close to a tree | No | A strike, ground current, side flash, or falling limb can cause injury. |
| Tent or other exposed outdoor spot | No | It does not provide the protection of a substantial building or enclosed vehicle. |
Ground current is electrical energy that moves through the ground after a lightning strike. Side flash is a lightning discharge that jumps from an object, such as a tree, to a nearby person. These are reasons that being near a tree can remain dangerous even if the tree itself is not struck directly.
A tree canopy is not a lightning shield. A tree may be struck, shed limbs, or conduct current through its trunk and the surrounding ground. There is no general distance from a tree that makes an outdoor spot safe during a storm, so do not rely on a guessed number of feet.
If you are already beneath a tree when thunder begins, leave promptly and move toward proper shelter. Do not wait under the branches for the rain to pass, and do not move to another tree as a workaround. Keep away from water and do not enter an open-sided structure expecting it to protect you from lightning.
Immediate Actions When Shelter Is Unavailable
If a substantial building or enclosed hard-topped vehicle cannot be reached at once, you are still exposed to risk. No outdoor posture makes a storm safe. A low crouch is only a last-resort way to reduce exposure while you continue toward proper shelter as soon as you can.
Use this order of action:
- Move away from isolated tall objects, including isolated trees, and from water.
- Seek lower terrain if it is available and does not put you in a flood-prone spot, ravine, or other hazard.
- If you remain unsheltered, crouch low with your feet together and minimize contact with the ground.
- Keep moving toward a substantial enclosed building or hard-topped, fully enclosed vehicle when it is possible to do so.
- Do not lie flat on the ground.
Lying flat increases the area of your body in contact with the ground and may increase exposure to ground current. The crouch does not eliminate lightning risk; it is a fallback, not a shelter plan. Avoid adding false precision, such as assuming a certain crouch, tree distance, or piece of outdoor equipment guarantees safety.
Planning scenario: A hiker hears thunder with no building or vehicle close by. The person should move away from an isolated tall tree and water, avoid low spots that could flood, and use the low crouch only while exposed and moving toward safer shelter when possible. This is a general safety example, not a documented case study.
For groups, agree on what to do before anyone goes outside: where shelter is, who checks on others, and how the group will respond when thunder is heard. A clear plan reduces the chance that people will split up or wait under trees while deciding what to do.
Post-Storm Timing and Safety Verification
The storm is not considered clear for outdoor activity just because rain has stopped or the sky looks brighter. Wait at least 30 minutes after the last thunder before resuming outdoor activity. If thunder is heard again, start the 30-minute count again.
Use this check before returning outside:
- Note the time of the last thunder.
- Remain inside a substantial building or hard-topped, fully enclosed vehicle for at least 30 minutes afterward.
- If thunder sounds again, reset the timer.
- Reassess weather and any other hazards, such as flooding or fallen branches, before leaving shelter.
This waiting period is a practical threshold from NWS lightning-safety guidance, not a guarantee that conditions cannot change. Do not use the end of rainfall, a brief break in clouds, or a phone’s lack of an alert as a substitute for the thunder rule.
Planning scenario: A sports group takes shelter in an enclosed building, then hears thunder again after the rain eases. The group should remain inside and begin a new 30-minute wait from that last thunder. A coach or organizer can make this easier by assigning one person to track the time.
The key decision is straightforward: stay sheltered while thunder is audible, then wait the full interval after the last thunder. Check the area for hazards before returning to outdoor activity.
Frequently Asked Questions
These quick answers cover common decisions people face when thunder begins outdoors. The main rule remains the same: do not use a tree or open-sided shelter as protection, and move to an enclosed building or hard-topped vehicle. If neither is available, reduce exposure as a last resort and keep seeking proper shelter.
Is it safe to stand under a large tree during a thunderstorm?
No. A tree can be struck, and lightning can travel through the tree or nearby ground. Falling branches are another risk.
Does a thick tree canopy protect me from lightning?
No. Leaves and branches do not make a tree a safe lightning shelter. Move toward a substantial enclosed building or hard-topped vehicle.
How close can I stand to a tree during a storm?
There is no general distance that makes an outdoor location safe. Do not shelter beneath or close to a tree; move toward proper shelter.
Is an open-sided pavilion safe?
No. A roof without full enclosure is not equivalent to a substantial enclosed building or hard-topped vehicle.
What should I do if I hear thunder but see no lightning?
Stop outdoor activity and head to proper shelter. Thunder is enough warning to act.
What if no building or vehicle is nearby?
Move away from isolated tall objects and water, and seek lower terrain that is not flood-prone. If still exposed, crouch low with feet together and minimize ground contact while moving toward shelter when possible.
Should I lie flat if lightning is nearby?
No. Lying flat increases the area of your body in contact with the ground. Use a low crouch only as a last resort; it does not make you safe.
When can I go back outside after a storm?
Wait at least 30 minutes after the last thunder. If you hear thunder again, restart the 30-minute wait.
These recommendations follow National Weather Service lightning-safety guidance. In short: leave trees behind, seek enclosed shelter promptly, and wait 30 minutes after the last thunder before returning outdoors.
(This article was written by one of our staff writers, Richard Montclair. Visit our Meet the Team page.)
