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Hurricane hazards: surge, wind, rain, tornadoes

This page explains the main hurricane hazards, which ones cause the most deaths, and the simple rule that keeps most people safe. Knowing what actually hurts people helps you spend your effort in the right place.

If you only do three things

  • Find out whether your home is in a storm surge evacuation zone.
  • Decide now where you would go if told to leave.
  • Learn the after-storm hazards, because they kill more people than the storm itself.

Storm surge: the leading cause of death

Storm surge is the rise in ocean water pushed onto land by a hurricane's winds. It is the leading cause of death in hurricanes. Historically, about half of hurricane deaths in the United States have come from surge.

Surge is not a wave. It is the whole sea level rising, sometimes by 3 to 5 meters (10 to 15 feet) or more, and staying high for hours. Waves ride on top of that raised water and make it worse, but the surge itself is a steady, spreading flood that moves inland through streets, canals, and low ground.

The water can rise fast. A neighborhood that is dry at dinner can be under a meter or more (several feet) of water by the time you finish washing up. Surge also arrives before the eye does, often while people still think they have time.

Water is heavy. Just 30 centimeters (1 foot) of moving water can sweep a car off the road, and a meter (3 feet) can push a house off its foundation. Cars, which many people count on for escape, are the first things to fail in surge.

You cannot outlast surge in a house

Once surge water is rising around you, there is no safe way to leave. Boats and rescue crews cannot reach you during the worst of the storm. The only way to survive surge is to not be there when it arrives.

The rule that emergency managers repeat every season is simple: run from the water, hide from the wind. If you live in a surge zone and officials tell you to leave, you leave. You do not need to go far, only to higher ground outside the zone, often just a few kilometers (a few miles) inland. If you are not in a surge zone and your home is sturdy, staying put and sheltering from the wind is usually safer than driving into the unknown.

In many places, local or national officials map surge and evacuation zones. Find yours on our page about evacuation zones and your local help page. Do not guess based on how far you are from the beach. Bays, rivers, and canals carry surge well inland.

Wind and flying debris

Hurricane winds tear off roofs, snap trees, and turn ordinary objects into projectiles. Most wind injuries come from debris, not from the wind itself. A branch, a section of fence, or a patio chair moving at highway speed will go through a window.

The strongest winds are in the eyewall, but tropical storm force winds arrive hours earlier and extend far from the center. Once sustained winds reach 63 km/h (39 mph), being outside or on the road becomes dangerous.

The best defense against wind is a sturdy building, an interior room, and staying away from windows. Bring in or tie down anything loose before the storm. If you live in a mobile home, plan to leave for any hurricane, because these structures do not stand up to hurricane force winds. See our page on mobile homes.

Inland flooding from rain

Rain flooding is the second leading cause of hurricane deaths, and in some years it is the first. Unlike surge, it can happen hundreds of kilometers (hundreds of miles) from the coast and days after landfall. Storms that stall or move slowly are the worst, because they drop rain on the same ground for hours.

Rivers and creeks often crest a day or two after the rain stops, so flooding can get worse while the sky is clearing. Mountain areas are at special risk because water funnels into valleys fast.

Most flood deaths happen in vehicles. It takes only 30 centimeters (1 foot) of water to float a car, and the road underneath may be washed away. Never drive around barricades and never try to cross flooded roads. Our page on flooding during a storm covers what to do if water reaches you.

Tornadoes in the outer bands

Hurricanes often produce tornadoes, mostly in the rain bands on the front right side of the storm. These tornadoes tend to be weaker and shorter lived than the ones on the Great Plains of the United States, but they form quickly and give little warning. They can happen well before the storm center arrives and hundreds of kilometers (hundreds of miles) from landfall.

Keep your phone alerts on during the entire storm. When a tornado warning comes, move to an interior room on the lowest floor and stay there until it expires. Read more on our tornadoes during a hurricane page.

Rip currents and high surf

A hurricane hundreds of kilometers (hundreds of miles) offshore can still kill people on the beach. Large swells travel far ahead of the storm and create strong rip currents that pull swimmers away from shore. Some years, more people die in rip currents from distant hurricanes than from storms that make landfall.

Stay out of the water when a tropical system is anywhere in the region, even if the weather looks fine. If you are caught in a rip current, do not fight it. Swim parallel to the shore until you are free, then swim back at an angle.

After the storm: the hazards that kill the most

More people die after a hurricane than during it. The causes are ordinary, which is what makes them dangerous. People let their guard down once the wind stops.

  • Carbon monoxide from generators, grills, or vehicles run indoors or too close to windows. It has no smell and kills people in their sleep.
  • Electrocution from downed power lines and from water that has touched live wiring.
  • Heat illness, because power is out, air conditioning is off, and people are working hard outdoors.
  • Cleanup accidents, including chain saw injuries, falls from ladders and roofs, and heart attacks from strenuous work.
  • Contaminated water and spoiled food.

Never run a generator indoors

Carbon monoxide has no smell. Run generators outside, at least 6 meters (20 feet) from any window, door, or vent.

Every one of these is preventable. Our after the storm section covers each in detail, including generator safety, returning home safely, and cleanup and mold.