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Seattle survival atlas

King County, Washington

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

Seattle’s biggest natural hazards are earthquakes, inland flooding and heat waves. In FEMA’s National Risk Index they make up 98% of the natural-hazard risk for King County, home to all of Seattle’s 784,777 residents. FEMA rates the county’s overall risk Very High. Here is what to do for each, step by step.

People
784,777
Census estimate, July 1, 2025. No. 18 in the U.S.
County
King County
All of Seattle’s residents. FEMA rates counties, not cities.
Overall risk
Very High
Score 99.68 of 100. No. 7 of the 30 largest U.S. cities.
Expected loss
$1.7 billion
A year, from all 18 natural hazards (FEMA estimate).
Top 3 hazards
98%
of the county’s risk comes from these three: Earthquake · Inland flooding · Heat wave.

What to do for Seattle’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 · 72% of the risk · Very High

Earthquake

FEMA score 99.90: higher than 99.9% of U.S. counties. Expected loss $1.2 billion a year.

RememberDrop. Cover. Hold on.
  1. Drop to your hands and knees.
  2. Cover your head and neck, under a sturdy table if one is close.
  3. Hold on until the shaking stops. Don't run outside or stand in a doorway.
Every step: What to do during an earthquake
Source // Ready.gov: Earthquakes · Great ShakeOut: Drop, Cover, and Hold On
No. 2 · 25% of the risk · Very High

Inland flooding

FEMA score 99.45: higher than 99.4% of U.S. counties. Expected loss $417 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. 3 · 1.1% of the risk · Relatively High

Heat wave

FEMA score 98.16: higher than 98.1% of U.S. counties. Expected loss $18.9 million a year.

RememberGet somewhere cool. Check on anyone who lives alone.
  1. Use air conditioning, or go to a library, mall or cooling center.
  2. Heat stroke signs: confusion, slurred speech, collapse; hot, dry or soaked skin; 103°F or higher.
  3. Call 911.
Every step: What to do in extreme heat and heat stroke
Source // National Weather Service: Heat safety · CDC/NIOSH: Heat-related illnesses
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 Seattle, ranked

Ranked by each hazard’s share of King 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 Earthquake 72% Very High 99.90 $1.2 billion Drop. Cover. Hold on.
2 Inland flooding 25% Very High 99.45 $417 million Turn around, don't drown.
3 Heat wave 1.1% Relatively High 98.16 $18.9 million Get somewhere cool. Check on anyone who lives alone.
4 Avalanche 0.7% Very High 99.26 $11.1 million Check your local avalanche center before backcountry travel.
5 Tsunami 0.4% Relatively Low 67.69 $6.3 million Strong or long shaking near the sea: go high now.
6 Tornado 0.2% Relatively Moderate 73.15 $3.5 million Lowest floor, interior room, cover your head.
7 Volcanic activity 0.1% Relatively High 97.39 $1.9 million Evacuate early. In ashfall, stay in and wear an N95.
8 Landslide <0.1% Relatively High 98.98 $1.7 million Follow local alerts. Leave when officials say so.
9 Coastal flooding <0.1% Relatively Moderate 71.00 $1.5 million Run from the water. Hide from the wind.
10 Ice storm <0.1% Relatively High 91.10 $1.3 million Stay off the roads. One warm room.
11 Winter weather <0.1% Relatively High 94.71 $815,000 Stay in your shelter, or stay with your car.
12 Lightning <0.1% Relatively Moderate 74.74 $750,000 When thunder roars, go indoors.
13 Wildfire <0.1% Relatively Low 79.45 $487,000 Leave early. Know two ways out.
14 Cold wave <0.1% Relatively Low 26.52 $449,000 One warm room. Never heat with an oven or a grill.
15 Strong wind <0.1% Very Low 4.48 $39,000 Shelter in an interior room, away from windows.
16 Hail <0.1% Very Low 3.14 $8,000 Large hail coming? Get inside a sturdy building and away from the windows.
17 Drought <0.1% Very Low 13.74 $240 Store water now: 1 gallon per person per day.
– Hurricane – Not applicable – – Know your evacuation zone. Told to go? Go early.

Source // FEMA National Risk Index v1.20 (December 2025), county 53033. 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.
  • King County is rated Very Low for social vulnerability and Very High for community resilience. Both feed into its overall rating.

Questions people ask

What natural disasters is Seattle most at risk for?

Seattle’s biggest natural hazards are earthquakes, inland flooding and heat waves. In FEMA’s National Risk Index they make up 98% of the natural-hazard risk for King County, home to all of Seattle’s 784,777 residents. FEMA rates the county’s overall risk Very High.

How does FEMA rate Seattle’s overall disaster risk?

FEMA’s National Risk Index rates the overall risk of King County Very High, with a score of 99.68 out of 100. The score is a percentile: King County’s overall risk is higher than 99.6% of U.S. counties. Expected losses from natural hazards there average $1.7 billion a year.

What should I do first to get ready in Seattle?

Write down your top three: earthquakes, inland flooding and heat waves. 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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