SOS.city · City atlas · Colorado

Denver survival atlas

Denver County, Colorado

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

Denver’s biggest natural hazards are inland flooding, hail and tornadoes. In FEMA’s National Risk Index they make up 87% of the natural-hazard risk for Denver County, home to all of Denver’s 740,613 residents. FEMA rates the county’s overall risk Relatively High. Here is what to do for each, step by step.

People
740,613
Census estimate, July 1, 2025. No. 19 in the U.S.
County
Denver County
All of Denver’s residents. FEMA rates counties, not cities.
Overall risk
Relatively High
Score 95.22 of 100. No. 28 of the 30 largest U.S. cities.
Expected loss
$222 million
A year, from all 18 natural hazards (FEMA estimate).
Top 3 hazards
87%
of the county’s risk comes from these three: Inland flooding · Hail · Tornado.

What to do for Denver’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 · Relatively High

Inland flooding

FEMA score 95.26: higher than 95.2% of U.S. counties. Expected loss $93.6 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 · 33% of the risk · Very High

Hail

FEMA score 99.87: higher than 99.8% of U.S. counties. Expected loss $72.4 million a year.

RememberLarge hail coming? Get inside a sturdy building and away from the windows.
  1. Go into a sturdy building now. Sheds and storage buildings are not safe.
  2. Stay away from windows. A small interior room on the lowest floor is best.
  3. In a car, you are safer than outside. If there is time, drive to the closest secure shelter.
Every step: What to do in a hail storm
Source // National Weather Service: During a thunderstorm · National Weather Service Melbourne: Severe thunderstorm safety rules
No. 3 · 13% of the risk · Relatively High

Tornado

FEMA score 97.86: higher than 97.8% of U.S. counties. Expected loss $28.0 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 Denver, ranked

Ranked by each hazard’s share of Denver 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% Relatively High 95.26 $93.6 million Turn around, don't drown.
2 Hail 33% Very High 99.87 $72.4 million Large hail coming? Get inside a sturdy building and away from the windows.
3 Tornado 13% Relatively High 97.86 $28.0 million Lowest floor, interior room, cover your head.
4 Cold wave 4.5% Relatively High 92.14 $10.1 million One warm room. Never heat with an oven or a grill.
5 Earthquake 3.3% Relatively Moderate 91.03 $7.4 million Drop. Cover. Hold on.
6 Lightning 2.0% Very High 98.56 $4.4 million When thunder roars, go indoors.
7 Strong wind 1.8% Relatively High 96.08 $4.1 million Shelter in an interior room, away from windows.
8 Heat wave 0.5% Relatively Low 71.48 $1.2 million Get somewhere cool. Check on anyone who lives alone.
9 Winter weather 0.3% Relatively High 91.94 $562,000 Stay in your shelter, or stay with your car.
10 Wildfire <0.1% Very Low 60.62 $105,000 Leave early. Know two ways out.
11 Landslide <0.1% Relatively Moderate 87.27 $49,000 Follow local alerts. Leave when officials say so.
12 Ice storm <0.1% Very Low 12.12 $8,000 Stay off the roads. One warm room.
13 Drought <0.1% Very Low 21.40 $7,000 Store water now: 1 gallon per person per day.
14 Volcanic activity <0.1% Very Low 73.61 $170 Evacuate early. In ashfall, stay in and wear an N95.
– Avalanche – Not applicable – – Check your local avalanche center before backcountry travel.
– Coastal flooding – Not applicable – – Run from the water. Hide from the wind.
– Hurricane – Not applicable – – Know your evacuation zone. Told to go? Go early.
– Tsunami – Not applicable – – Strong or long shaking near the sea: go high now.

Source // FEMA National Risk Index v1.20 (December 2025), county 08031. 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.
  • Denver County is rated Very Low for social vulnerability and Relatively High for community resilience. Both feed into its overall rating.

Questions people ask

What natural disasters is Denver most at risk for?

Denver’s biggest natural hazards are inland flooding, hail and tornadoes. In FEMA’s National Risk Index they make up 87% of the natural-hazard risk for Denver County, home to all of Denver’s 740,613 residents. FEMA rates the county’s overall risk Relatively High.

How does FEMA rate Denver’s overall disaster risk?

FEMA’s National Risk Index rates the overall risk of Denver County Relatively High, with a score of 95.22 out of 100. The score is a percentile: Denver County’s overall risk is higher than 95.2% of U.S. counties. Expected losses from natural hazards there average $222 million a year.

What should I do first to get ready in Denver?

Write down your top three: inland flooding, hail 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.

More city atlases

San AntonioInland flooding · Tornado · HailFort WorthInland flooding · Tornado · HailAustinInland flooding · Tornado · HailChicagoInland flooding · Cold wave · TornadoAll 30 citiesAnd the 14 survival guides

Made by the people, for the people. Independent, not a government site. FEMA and the Census Bureau are our sources, not our partners.