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Detroit survival atlas

Wayne County, Michigan

Reviewed · Data: FEMA National Risk Index v1.20 (December 2025) · U.S. Census Bureau Vintage 2025 · By SOS.city, made by the people for the people
In an emergency, call 911

Detroit’s biggest natural hazards are inland flooding, cold waves and tornadoes. In FEMA’s National Risk Index they make up 84% of the natural-hazard risk for Wayne County, home to all of Detroit’s 649,095 residents. FEMA rates the county’s overall risk Relatively High. Here is what to do for each, step by step.

People
649,095
Census estimate, July 1, 2025. No. 26 in the U.S.
County
Wayne County
All of Detroit’s residents. FEMA rates counties, not cities.
Overall risk
Relatively High
Score 98.95 of 100. No. 16 of the 30 largest U.S. cities.
Expected loss
$402 million
A year, from all 18 natural hazards (FEMA estimate).
Top 3 hazards
84%
of the county’s risk comes from these three: Inland flooding · Cold wave · Tornado.

What to do for Detroit’s top hazards

The one rule to remember, then the first steps, word for word from our guides. Each guide lists its sources.

No. 1 · 59% of the risk · Very High

Inland flooding

FEMA score 99.39: higher than 99.3% of U.S. counties. Expected loss $237 million a year.

RememberTurn around, don't drown.
  1. Get to high ground now.
  2. Never walk, swim or drive into floodwater. 6 inches of moving water can knock you down; 12 inches carries away most cars.
  3. Car stalls in rising water: get out to higher ground if you safely can. Trapped in fast water: stay inside; if water rises inside, get on the roof.
Every step: What to do in a flood or flash flood
Source // National Weather Service: Turn Around Don’t Drown · Ready.gov: Floods
No. 2 · 15% of the risk · Very High

Cold wave

FEMA score 99.74: higher than 99.7% of U.S. counties. Expected loss $59.8 million a year.

RememberOne warm room. Never heat with an oven or a grill.
  1. One warm room at home. Never heat with an oven or a grill.
  2. Signs: shivering, confusion, fumbling hands, slurred speech, drowsiness.
  3. Get them somewhere warm. Take off wet clothing.
Every step: What to do in a winter storm or blizzard
Source // National Weather Service: Winter safety · National Weather Service: During a winter storm
No. 3 · 11% of the risk · Very High

Tornado

FEMA score 99.49: higher than 99.4% of U.S. counties. Expected loss $43.8 million a year.

RememberLowest floor, interior room, cover your head.
  1. Go to the lowest floor: a small interior room away from windows.
  2. Cover your head and neck.
  3. In a mobile home or a car: get to a sturdy building.
Every step: What to do in a tornado warning
Source // National Weather Service: During a tornado · National Weather Service: Tornado safety
Emergency911
Poison Help1-800-222-1222
Can’t reach family?Text, don’t call. Texts often get through when calls don’t.

All 18 natural hazards in Detroit, ranked

Ranked by each hazard’s share of Wayne County’s risk in FEMA’s National Risk Index. The score compares the county with every other U.S. county for that one hazard.

#HazardShare of riskFEMA ratingScoreExpected loss a yearThe rule
1 Inland flooding 59% Very High 99.39 $237 million Turn around, don't drown.
2 Cold wave 15% Very High 99.74 $59.8 million One warm room. Never heat with an oven or a grill.
3 Tornado 11% Very High 99.49 $43.8 million Lowest floor, interior room, cover your head.
4 Heat wave 7.9% Relatively High 99.29 $31.8 million Get somewhere cool. Check on anyone who lives alone.
5 Strong wind 3.2% Very High 99.71 $12.7 million Shelter in an interior room, away from windows.
6 Earthquake 2.5% Relatively Moderate 94.65 $9.9 million Drop. Cover. Hold on.
7 Ice storm 0.7% Very High 99.00 $2.8 million Stay off the roads. One warm room.
8 Lightning 0.6% Very High 98.25 $2.5 million When thunder roars, go indoors.
9 Winter weather 0.1% Relatively High 94.74 $491,000 Stay in your shelter, or stay with your car.
10 Hail <0.1% Relatively Low 46.53 $174,000 Large hail coming? Get inside a sturdy building and away from the windows.
11 Hurricane <0.1% Very Low 57.78 $120,000 Know your evacuation zone. Told to go? Go early.
12 Coastal flooding <0.1% Relatively Low 49.60 $90,000 Run from the water. Hide from the wind.
13 Wildfire <0.1% Very Low 54.38 $46,000 Leave early. Know two ways out.
14 Landslide <0.1% Very Low 58.20 $2,000 Follow local alerts. Leave when officials say so.
– Avalanche – Not applicable – – Check your local avalanche center before backcountry travel.
– Drought – No rating – – Store water now: 1 gallon per person per day.
– Tsunami – Insufficient data – – Strong or long shaking near the sea: go high now.
– Volcanic activity – Not applicable – – Evacuate early. In ashfall, stay in and wear an N95.

Source // FEMA National Risk Index v1.20 (December 2025), county 26163. Rules: SOS.city survival guides.

How to read these numbers

  • Share of risk. For each hazard, FEMA estimates the loss each year to buildings, people and farms, then adjusts it for social vulnerability and community resilience. The county’s overall risk is the sum of all 18, so the share shows how much of it each hazard carries.
  • Score. A percentile from 0 to 100. A score of 99.5 means the county’s risk for that hazard is higher than 99.5% of U.S. counties.
  • Rating. FEMA sorts counties into five groups, from Very Low to Very High.
  • Big places rank high. Expected losses grow with the number of people and buildings exposed, so large urban counties rank high on many hazards. A high rating means plan for it, not that it will happen this year.
  • County, not street. These ratings cover the whole county. For flood risk at your address, look it up on the FEMA Flood Map Service Center.
  • Wayne County is rated Relatively High for social vulnerability and Relatively Moderate for community resilience. Both feed into its overall rating.

Questions people ask

What natural disasters is Detroit most at risk for?

Detroit’s biggest natural hazards are inland flooding, cold waves and tornadoes. In FEMA’s National Risk Index they make up 84% of the natural-hazard risk for Wayne County, home to all of Detroit’s 649,095 residents. FEMA rates the county’s overall risk Relatively High.

How does FEMA rate Detroit’s overall disaster risk?

FEMA’s National Risk Index rates the overall risk of Wayne County Relatively High, with a score of 98.95 out of 100. The score is a percentile: Wayne County’s overall risk is higher than 98.9% of U.S. counties. Expected losses from natural hazards there average $402 million a year.

What should I do first to get ready in Detroit?

Write down your top three: inland flooding, cold waves and tornadoes. Turn on Emergency Alerts on every phone and sign up for your county’s alerts. Store water: 1 gallon per person per day for at least 3 days, 2 weeks if you can.

Sources

Every number on this page comes from these public datasets. We check them when we review the page.

General safety information, not medical advice. In an emergency, call 911 and follow local officials.

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