Project Trinetra / Preparedness / Thunderstorm Thunderstorm Lightning kills more people than tornadoes or hurricanes each year
8 things to do before · 8 steps during · 8 after · 5 questions answered
Last updated 2026-09-25 . Written by Project Trinetra, a program of the 501(c)(3) nonprofit Unravel The Love. It is not an official government publication and does not replace instructions from your local emergency authorities.
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Open the live map Before — Before the StormThunderstorms can produce lightning, hail, flash floods, and tornadoes. Preparation is key.
# Do this 1 Enable severe weather alerts on your phone 2 Identify sturdy buildings for shelter near work, school, and home 3 Get surge protectors for sensitive electronics 4 Trim dead branches that could become projectiles in high winds 5 Secure or bring in outdoor furniture, trash cans, and decorations 6 Clean gutters and drains to prevent flash flooding 7 Prepare emergency kit with flashlight, batteries, and water 8 Have a family communication plan in case you are separated
During — During a ThunderstormLightning is the biggest threat. Get indoors immediately when thunder is heard.
# Step 1 Move indoors to a sturdy building — NOT a shed, carport, or open structure 2 If no building available, get in a hard-topped vehicle with windows closed 3 Stay away from windows, doors, porches, and concrete surfaces 4 Do NOT use corded phones or plumbing (lightning travels through wires and pipes) 5 Unplug sensitive electronics to prevent surge damage 6 If caught outside: avoid hilltops, open fields, tall isolated trees, and bodies of water 7 If caught outside with no shelter: crouch low with feet together, do NOT lie flat 8 Wait 30 minutes after the last thunder before going outside
After — After the Storm PassesThunderstorm damage can include downed trees, power lines, and flash flooding.
# Step 1 Stay away from downed power lines — assume all are energized 2 Check your property for damage from wind, hail, or fallen trees 3 Avoid flooded areas — just 6 inches of moving water can knock you down 4 If someone is struck by lightning, call 911 immediately — they are safe to touch 5 Begin CPR on lightning victims if they are not breathing 6 Report downed trees and power lines to your utility company 7 Document any property damage with photos for insurance 8 Check on neighbors, especially elderly or disabled
Supplies specific to this hazard · Surge protectors for electronics · Battery-powered weather radio · Flashlights with extra batteries · Emergency water supply (1 gallon per person per day) · First aid kit Questions people ask What should I do if caught outside during lightning? Lightning is the most immediate danger in a thunderstorm. If you're caught outside:
· Get indoors immediately — a substantial building or hard-topped vehicle· Avoid : Tall trees, open fields, hilltops, water, metal fences, and poles· If no shelter is available, crouch low with feet together, hands on ears, head tucked — minimize ground contact · Do NOT lie flat — this increases your ground contact area· Stay away from isolated trees — they attract lightning Wait at least 30 minutes after the last thunder before going back outside. Lightning can strike 10+ miles from the storm.
Full Thunderstorm guide — before, during and after → How far away is a thunderstorm based on thunder delay? You can estimate lightning distance using the flash-to-bang method :
· Count the seconds between the lightning flash and the thunder · Divide by 5 = distance in miles (divide by 3 for km)· Example: 10 seconds = about 2 miles away If the count is 30 seconds or less (6 miles), you are in danger. Seek shelter immediately.
This is the 30-30 rule : Take shelter when the flash-to-bang is 30 seconds or less, and stay sheltered for 30 minutes after the last thunder.
Full Thunderstorm guide — before, during and after → Is it safe to shower or use plumbing during a thunderstorm? No — avoid all plumbing during a thunderstorm. Lightning can travel through metal pipes and water.
Specifically, avoid:
· Showers and baths · Washing dishes · Washing hands (use hand sanitizer instead) Also avoid:
· Corded phones (cell phones are fine) · Desktop computers plugged into the wall · Anything connected to an electrical outlet The risk is low but real — lightning strikes to homes travel through wiring and plumbing.
Full Thunderstorm guide — before, during and after → How do I protect my electronics from a lightning surge? Power surges from lightning can destroy electronics even if lightning doesn't strike your home directly:
· Unplug sensitive electronics (TV, computer, gaming systems) during storms — surge protectors help but can't stop a direct strike· Use a whole-house surge protector installed at your electrical panel (best investment, $200-500)· Use UPS (battery backup) for computers — provides surge protection and time to shut down safely· Unplug your internet modem and router — surges travel through cable/phone lines tooIf you hear thunder, it's already time to unplug. Don't wait for the storm to be overhead.
Full Thunderstorm guide — before, during and after → What is the 30-30 lightning safety rule? The 30-30 rule is the simplest lightning safety guide:
First 30 : When you see lightning, count seconds until you hear thunder. If it's 30 seconds or less , go inside immediately. The storm is within 6 miles — close enough for lightning to reach you.
Second 30 : After the last thunder, wait 30 minutes before going back outside. Lightning can strike well after rain stops.
Remember: "When thunder roars, go indoors." There is no safe place outdoors during a thunderstorm. Substantial buildings and hard-topped vehicles are the only safe shelters.
Full Thunderstorm guide — before, during and after → Quick facts · When thunder roars, go indoors. Lightning can strike 10+ miles from a storm. · Use the 30-30 rule: shelter when flash-to-bang is 30 seconds or less, wait 30 minutes after last thunder. · Never shower, wash dishes, or use plumbing during a thunderstorm — lightning travels through pipes. · Unplug sensitive electronics when you hear thunder — surge protectors can't stop a direct lightning strike. · If caught outside during lightning, crouch low with feet together — never lie flat on the ground. ← All preparedness guides
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