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San Diego survival atlas

San Diego County, California

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

San Diego’s biggest natural hazards are inland flooding, wildfire and earthquakes. In FEMA’s National Risk Index they make up 97% of the natural-hazard risk for San Diego County, home to all of San Diego’s 1.4 million residents. FEMA rates the county’s overall risk Very High. Here is what to do for each, step by step.

People
1,406,106
Census estimate, July 1, 2025. No. 8 in the U.S.
County
San Diego County
All of San Diego’s residents. FEMA rates counties, not cities.
Overall risk
Very High
Score 99.71 of 100. No. 5 of the 10 largest U.S. cities.
Expected loss
$1.5 billion
A year, from all 18 natural hazards (FEMA estimate).
Top 3 hazards
97%
of the county’s risk comes from these three: Inland flooding · Wildfire · Earthquake.

What to do for San Diego’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 · 42% of the risk · Very High

Inland flooding

FEMA score 99.74: higher than 99.7% of U.S. counties. Expected loss $648 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 · 28% of the risk · Very High

Wildfire

FEMA score 100.00: the highest of any U.S. county. Expected loss $430 million a year.

RememberLeave early. Know two ways out.
  1. Grab the go-bags, the people and the pets. Go.
  2. Use the routes officials name, not shortcuts.
  3. In smoke, wear an N95. Cloth masks don't filter it.
Every step: What to do when a wildfire is coming
Source // Ready.gov: Wildfires · Ready, Set, Go! (International Association of Fire Chiefs)
No. 3 · 28% of the risk · Relatively High

Earthquake

FEMA score 99.68: higher than 99.6% of U.S. counties. Expected loss $426 million 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
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 San Diego, ranked

Ranked by each hazard’s share of San Diego 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 42% Very High 99.74 $648 million Turn around, don't drown.
2 Wildfire 28% Very High 100.00 $430 million Leave early. Know two ways out.
3 Earthquake 28% Relatively High 99.68 $426 million Drop. Cover. Hold on.
4 Heat wave 1.6% Relatively High 98.74 $24.2 million Get somewhere cool. Check on anyone who lives alone.
5 Landslide 0.2% Relatively High 99.49 $3.1 million Follow local alerts. Leave when officials say so.
6 Tornado 0.1% Relatively Low 64.40 $2.3 million Lowest floor, interior room, cover your head.
7 Tsunami 0.1% Relatively Low 52.30 $1.6 million Strong or long shaking near the sea: go high now.
8 Coastal flooding <0.1% Relatively Moderate 72.80 $1.5 million Run from the water. Hide from the wind.
9 Lightning <0.1% Relatively Moderate 80.94 $829,000 When thunder roars, go indoors.
10 Hail <0.1% Relatively Moderate 77.00 $825,000 Get indoors, away from windows.
11 Strong wind <0.1% Relatively Moderate 52.00 $642,000 Shelter in an interior room, away from windows.
12 Drought <0.1% Relatively Low 59.41 $299,000 Store water now: 1 gallon per person per day.
13 Winter weather <0.1% Relatively Low 48.34 $67,000 Stay in your shelter, or stay with your car.
14 Hurricane <0.1% Very Low 8.30 $1,000 Know your evacuation zone. Told to go? Go early.
15 Cold wave <0.1% Very Low 3.14 $521 One warm room. Never heat with an oven or a grill.
16 Avalanche <0.1% Very Low 32.16 $137 Check your local avalanche center before backcountry travel.
17 Volcanic activity <0.1% Very Low 33.87 $3 Evacuate early. In ashfall, stay in and wear an N95.
– Ice storm – Not applicable – – Stay off the roads. One warm room.

Source // FEMA National Risk Index v1.20 (December 2025), county 06073. 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.
  • San Diego County is rated Relatively Low for social vulnerability and Very Low for community resilience. Both feed into its overall rating.

Questions people ask

What natural disasters is San Diego most at risk for?

San Diego’s biggest natural hazards are inland flooding, wildfire and earthquakes. In FEMA’s National Risk Index they make up 97% of the natural-hazard risk for San Diego County, home to all of San Diego’s 1.4 million residents. FEMA rates the county’s overall risk Very High.

How does FEMA rate San Diego’s overall disaster risk?

FEMA’s National Risk Index rates the overall risk of San Diego County Very High, with a score of 99.71 out of 100. The score is a percentile: San Diego County’s overall risk is higher than 99.7% of U.S. counties. Expected losses from natural hazards there average $1.5 billion a year.

What should I do first to get ready in San Diego?

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