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Colorado Environment & Hazard Risk

2 counties rated high or very high risk. 46,814 storm events since 1996, #16 among states.

Expected yearly loss
$2.17B
$375 per person
Storm events since 1996
46,814
Most often hail
Flood insurance policies
11,282
$90.67M in claims paid
Superfund sites
24
262 toxic release facilities

Risk by county

FEMA National Risk Index rating, highest risk first

CountyOverall riskTop hazardFlood policiesFlood claims paid
Denver CountyHighHail765$719K
Jefferson CountyHighHail1,293$3.06M
El Paso CountyModerateWinter weather1,208$6M
Arapahoe CountyModerateHail677$1.04M
Adams CountyModerateHail283$594K
Boulder CountyModerateLightning2,543$50.1M
Larimer CountyModerateLightning794$15.15M
Weld CountyModerateHail325$5.66M
Douglas CountyModerateLightning311$661K
Pueblo CountyModerateLightning106$332K
Eagle CountyLowAvalanche213$270K
La Plata CountyLowWildfire336$1.26M
Mesa CountyLowLandslide201$293K
Fremont CountyLowLightning184$344K
Garfield CountyLowLandslide103$93.72K
Summit CountyLowAvalanche145$20.32K
Logan CountyLowHail173$847K
Pitkin CountyLowAvalanche167$236K
Morgan CountyLowHail78$433K
Delta CountyLowLandslide32$86.06K
Chaffee CountyLowLandslide75$307K
Otero CountyLowLightning40$1.76M
Grand CountyLowAvalanche33$46.18K
Montrose CountyLowLightning75$60.13K
Prowers CountyLowDrought17$29.73K
Montezuma CountyLowWildfire63$19.6K
Clear Creek CountyLowAvalanche73$42.94K
Rio Grande CountyLowLandslide95$14.32K
Gunnison CountyLowLandslide126$86.88K
Alamosa CountyVery LowDrought40$4,195
Teller CountyVery LowWildfire37$12.02K
Rio Blanco CountyVery LowLandslide15$31.03K
Yuma CountyVery LowHail9$140K
Elbert CountyVery LowWildfire17-
Broomfield CountyVery LowHail75$179K
Archuleta CountyVery LowWildfire77$123K
Routt CountyVery LowLandslide151$415K
Kit Carson CountyVery LowHail--
Huerfano CountyVery LowWildfire34$1,116
Las Animas CountyVery LowWildfire7$10.99K
Baca CountyVery LowDrought--
Conejos CountyVery LowAvalanche10-
Park CountyVery LowWildfire25$343
San Miguel CountyVery LowAvalanche147$133K
Ouray CountyVery LowLandslide24$33.73K
Saguache CountyVery LowLandslide2$5,442
Phillips CountyVery LowDrought5$7,402
Moffat CountyVery LowLandslide20-
Washington CountyVery LowHail1-
Jackson CountyVery LowAvalanche--
Dolores CountyVery LowLandslide4-
San Juan CountyVery LowAvalanche2$1,144
Lincoln CountyVery LowHail5$4,362
Costilla CountyVery LowLandslide10$10.32K
Sedgwick CountyVery LowDrought1-
Gilpin CountyVery LowWildfire11$1,462
Lake CountyVery LowLandslide8$2,582
Bent CountyVery LowDrought2-
Mineral CountyVery LowAvalanche--
Custer CountyVery LowLandslide-$769
Crowley CountyVery LowWildfire--
Kiowa CountyVery LowDrought--
Cheyenne CountyVery LowDrought--
Hinsdale CountyVery LowLandslide9-

Costliest hazards

Expected annual loss in Colorado, all counties combined

  • Hail$341M/yr · 11 counties high
  • Wildfire$211M/yr · 5 counties high
  • Tornado$188M/yr · 9 counties high
  • Cold wave$129M/yr · 6 counties high
  • Avalanche$95.62M/yr · 23 counties high
  • Lightning$85.11M/yr · 24 counties high
  • Strong wind$44.28M/yr · 10 counties high
  • Earthquake$41.39M/yr
  • Drought$21.94M/yr · 4 counties high
  • Winter weather$20.54M/yr · 10 counties high

Storm events by type

Since 1996: 319 deaths, $10.85B in property and crop damage

  • Hail13,055
  • Winter Weather5,859 · 13 deaths
  • Winter Storm5,496 · 4 deaths
  • High Wind4,182 · 11 deaths
  • Thunderstorm Wind3,792 · 14 deaths
  • Heavy Snow3,215 · 4 deaths
  • Drought3,045
  • Flash Flood1,562 · 29 deaths
  • Tornado1,352 · 3 deaths
  • Heavy Rain792 · 2 deaths
  • Wildfire668 · 15 deaths
  • Frost/Freeze611

Events per year

Storm events per year in Colorado

Most damaging storms

Since 2017, ranked by deaths, injuries and damage

  • Hail2.75" hail05/08/2017

    Edgewater, Jefferson County

    $2.3B damage

    What happened

    The estimated damage is for the entire episode.

  • Wildfire12/30/2021

    Boulder & Jefferson Counties Below 6000 Feet / W Broomfield County

    2 deaths, 6 injured, $2B damage

    What happened

    Marshall Fire devastated portions of Marshall, Superior and Louisville. Strong downslope winds, with gusts up to 100 mph, fanned a grass fire that originated near the town of Marshall and quickly spread east to Superior and Louisville. The fire was the costliest fire in state history, and residential and business property losses alone were estimated to be slightly over $2 Billion. In all, 1,094 homes were destroyed and 266 homes were damaged. In addition, 7 commercial properties were destroyed and 30 others sustained damage. Tens of thousands fled the fire. Two people died in the fire, while six others were injured.

  • Ice Storm01/09/2017

    Grand Valley

    500 injured

    What happened

    Freezing rain, up to a half inch thick, quickly accumulated on roads and other surfaces at the beginning of the morning commute. There were hundreds of vehicle accidents and many roads were closed due to crashed vehicles blocking those roads. There were numerous injuries to those who slipped and fell. In fact, emergency rooms at hospitals in the Grand Valley exceeded their daily admittance records with over 200 people treated for broken bones and other blunt force injuries. Schools were closed throughout the Grand Valley, and many businesses were negatively impacted by either not opening, opening late, or the lack of customers.

  • Hail3" hail06/19/2018

    Englewood, Arapahoe County

    $276M damage

    What happened

    The property estimate value was the total storm damage summary for the event.

  • Wildfire10/14/2020

    Grand & Summit Counties Below 9000 Feet

    2 deaths, $167M damage

    What happened

    The East Troublesome Fire destroyed 555 structures. Two fatalities were confirmed. Nine buildings suffered major damage and 34 sustained minor damage. Among the buildings destroyed, 366 were residential and 189 were outbuildings. Ten buildings belonging to businesses were destroyed in the fire. Grand County estimated that debris removal could exceed over 30,000 cubic yards and cost more than $27 million to haul off. The property damage estimate only includes the destroyed residences and outbuildings.

  • Hail2.75" hail08/06/2018

    Colorado Spgs, El Paso County

    8 injured, $173M damage

    What happened

    Eight persons were transported to the hospital from the Cheyenne Mountain Zoo. Time and hail estimated.

Flood insurance

National Flood Insurance Program policies and claims

11,282 homes in Colorado have flood insurance, about 0.6% of residential buildings. In high-risk flood zones, 5,417 of 22,669 homes (24%) are insured.

Flood claims paid per year in Colorado
  • Late summer storms$69.59M · 2,155 claims
  • Flooding$728K · 113 claims
  • Colorado Burn Scar Flash Flooding$270K · 3 claims

Drinking water

1,058 community water systems serve about 7,195,786 people

Since 2021, 269 systems reported 1,572 health-based violations. 185 systems had a violation of any kind still open at last report. These had the most:

  • May Valley WaServes 1,500 · Groundwater · Private193 health violations+30 monitoring or reporting
  • Valley WcServes 270 · Groundwater · Private74 health violations+22 monitoring or reporting
  • South Swink Water AuthorityServes 622 · Groundwater · Local government60 health violations
  • Beehive Water AssociationServes 154 · Groundwater · Private51 health violations+38 monitoring or reporting
  • Patterson Valley WcServes 96 · Groundwater · Private44 health violations+11 monitoring or reporting
  • Eureka WcServes 498 · Groundwater · Private43 health violations+90 monitoring or reporting
  • Manzanola Town ofServes 497 · Groundwater · Local government33 health violations+13 monitoring or reporting
  • Fayette WcServes 75 · Groundwater · Private33 health violations+17 monitoring or reporting

Select a county above to see every system that serves it.

Climate in the largest cities

1991-2020 normals from the nearest NOAA weather station

CityJuly highJan lowRainSnow
Denver91°F21°F15.9 in40.7 in
Colorado Springs81°F16°F--
Aurora90°F17°F--
Fort Collins87°F18°F15.9 in51.4 in
Lakewood86°F21°F17.5 in58.0 in
Thornton91°F19°F14.5 in44.8 in
Arvada88°F17°F17.1 in75.5 in
Pueblo92°F18°F12.6 in14.8 in

Pollution sites

24 Superfund sites and 262 toxic release facilities

Superfund sites

All 24 in Colorado

Facilities in Colorado reported 28.0 million lbs of toxic releases in 2024, 1.9 million lbs of it into the air.

Frequently asked questions

What is the biggest natural hazard in Colorado?
By expected annual loss, hail costs the most in Colorado ($341M a year), according to FEMA's National Risk Index.
How many storms hit Colorado each year?
NOAA recorded 46,814 storm events in Colorado since 1996, about 1,510 a year. The most common type is hail.
How many homes in Colorado have flood insurance?
11,282 residential flood insurance policies are in force in Colorado. Since 1978 the National Flood Insurance Program has paid $90.67M on 5,567 claims here.
How many Superfund sites are in Colorado?
Colorado has 24 Superfund sites on or deleted from EPA's National Priorities List.

Source: FEMA, NOAA, EPA · Last updated 08/01/2026 · Storm counts include events in forecast zones that touch each county. This product uses the FEMA OpenFEMA API, but is not endorsed by FEMA.