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Natural hazard risk in Boulder County, Colorado

Updated October 30, 2026. Based on FEMA, NOAA and OpenFEMA data. Published by Humblebee.

FEMA overall Risk Index rating: Relatively Moderate (score 90.7 of 100)[5]

Expected annual loss (FEMA)
$125.3 million[1]
Federal disaster declarations since 1969
17[2]
NFIP flood claims paid, 1978 to 2026
$50.1 million[3]
Tornadoes recorded, 1950 to 2024
11[4]

FEMA's National Risk Index (version 1.20, December 2025) gives Boulder County an overall Risk Index rating of Relatively Moderate, with a score of 90.7 out of 100[5]. The hazards with the highest FEMA scores within the county are lightning, hail and wildfire[6].

FEMA risk ratings for each hazard

Ratings and expected losses from the FEMA National Risk Index. Each rating compares this county with all US counties for that hazard, from Very Low to Very High. They are planning estimates, not predictions, and they do not describe any single property.

FEMA estimates Expected Annual Loss from all 18 natural hazards at $125.3 million a year[1]. FEMA's sorted loss values put inland flooding first at $69.1 million a year, then wildfire at $15.7 million a year and tornado at $12.4 million a year[7]. Expected Annual Loss is FEMA's estimate of the average economic loss in dollars from natural hazards each year[8]. The index is not meant to predict next year's damage[8]. FEMA rates Social Vulnerability Very Low, with a score of 11.3[9]. FEMA rates Community Resilience Very High, with a score of 91.2[10]. FEMA rates coastal flooding, hurricane and tsunami as Not Applicable for the county[11].

Hazards sorted by FEMA hazard-type Risk Index score, highest first
HazardFEMA risk ratingExpected annual loss
LightningVery High$5.9 million[12]
HailRelatively High$10.3 million[13]
WildfireRelatively High$15.7 million[14]
Winter WeatherRelatively High$1.1 million[15]
TornadoRelatively High$12.4 million[16]
Inland FloodingRelatively Moderate$69.1 million[17]
LandslideRelatively Moderate$78,000[18]
AvalancheRelatively High$1.8 million[19]
Strong WindRelatively High$2.3 million[20]
EarthquakeRelatively Low$2.4 million[21]
Ice StormRelatively Moderate$354,000[22]
Cold WaveRelatively Moderate$3.0 million[23]
Volcanic ActivityVery Low$79[24]
Heat WaveRelatively Low$815,000[25]
DroughtRelatively Low$79,000[26]

Rated Not Applicable by FEMA for this county: coastal flooding, hurricane, tsunami[11].

Social vulnerability and community resilience

FEMA uses these two ratings to scale expected losses into the Risk Index.

FEMA measureRatingScore
Social vulnerabilityVery Low11.3[9]
Community resilienceVery High91.2[10]

Flooding and flood insurance

FEMA rates inland flooding Relatively Moderate on the Risk Index and Relatively High for Expected Annual Loss[17]. OpenFEMA lists 2,543 residential flood insurance contracts in force as of 2026-08-03, a penetration rate of 2.3%[27]. Inside FEMA's mapped Special Flood Hazard Area there were 2,870 residential structures and 1,276 flood insurance contracts, a rate of 44.5%[27]. OpenFEMA's NFIP claims show 1,784 claims filed for losses from 1978 to 2026, and NFIP paid $50.1 million in total[3]. To learn about the flood zone of an address, use FEMA's Flood Map Service Center[28].

Measure Value
Inland Flooding, FEMA risk rating[17] Relatively Moderate, $69.1 million expected loss a year
NFIP residential flood policies in force (2026)[27] 2,543 of 111,369 homes
Homes in FEMA's mapped high-risk flood area (SFHA)[27] 2,870, of which 1,276 insured
NFIP flood claims, 1978 to 2026[3] 1,784 filed, $50.1 million paid

Is a specific address in a flood zone? Only FEMA's flood maps answer that, property by property[28]. This page describes the whole county.

Search an address on the FEMA Flood Map Service Center

Disaster declarations and tornado records

OpenFEMA lists 17 federal disaster declarations for natural hazards that include Boulder County since 1969[2]. By incident type, fire accounts for 9 and flood for 5[2]. The most recent is FM-5525-CO, Stone Mountain Fire, declared 2024-07-31[29]. NOAA's tornado database records 11 tornadoes touching the county from 1950 to 2024, and the most recent was on 2015-06-04[4].

Federal disaster declarations for natural hazards that include Boulder County, since 1969
Incident type Declarations
Fire[2] 9
Flood[2] 5
Snowstorm[2] 2
Coastal Storm[2] 1
Most recent declarations
Declaration Incident Declared
FM-5525-CO[29] Stone Mountain Fire 2024-07-31
DR-4634-CO[29] Wildfires And Straight-Line Winds 2021-12-31
FM-5423-CO[29] Marshall Fire 2021-12-30
FM-5379-CO[29] Calwood Fire 2020-10-17
DR-4229-CO[29] Severe Storms, Tornadoes, Flooding, Landslides, And Mudslides 2015-07-16

How to prepare

Steps from Ready.gov, FEMA's preparedness site, for the hazards with the highest FEMA ratings here. Follow instructions from local officials and the National Weather Service when a warning is issued.

Wildfires

Before

  • Sign up for community alerts and watch for air quality alerts.
  • Make sure everyone knows the evacuation plan, including for school, work and other places you go often.
  • Keep a fire-resistant zone of at least 30 feet around your home, clear of leaves and debris.
  • Use fire-resistant building materials and keep a hose long enough to reach every part of your property.
  • Pick a room you can seal off from outside air and keep a portable air cleaner ready.

During

  • Leave right away when authorities tell you to evacuate.
  • If you are trapped, call 9-1-1 with your location and turn on lights to help rescuers find you.
  • If you are not ordered to leave but there is smoke, stay in a safe indoor place or go to a community building with less smoke.

Source: Ready.gov, wildfires

Winter storms and cold

Before

  • Insulate your home and learn how to keep pipes from freezing.
  • Install and test smoke and carbon monoxide detectors with battery backup.
  • Keep several days of supplies in case the power goes out, including medication and pet needs.
  • Put an emergency kit in your car with jumper cables, sand, blankets, water and snacks, and keep the tank full.

During

  • Under a winter storm warning, find shelter right away.
  • Stay off the roads if you can. If you are stuck in your car, stay inside it.
  • Run generators and grills only outdoors, away from windows, and never heat your home with an oven or stove.

Source: Ready.gov, winter storms and cold

Tornadoes

Before

  • Learn the warning signs: a rotating funnel cloud, an approaching cloud of debris or a loud roar like a freight train.
  • Sign up for community warning systems and learn what your local sirens sound like.
  • Pick a safe spot, such as a safe room built to FEMA criteria or an ICC 500 storm shelter, and practice getting there.
  • Include your pets in the household emergency plan.
  • Keep supplies, food, water and medication in case you have to stay home for a long time.

During

  • Go right away to the safe place you picked in advance.
  • Protect your head and neck with your arms and stay away from windows, doors and outside walls.
  • No place in a car is fully safe. If you can get lower than the road, leave the car and lie down there.

Source: Ready.gov, tornadoes

Questions people ask

Is Boulder County at risk of flooding?
FEMA rates inland flooding Relatively Moderate compared with other US counties, and its Expected Annual Loss rating is Relatively High[17]. For a specific address, check FEMA's Flood Map Service Center[28].
Does Boulder County get tornadoes?
NOAA's tornado database records 11 tornadoes touching the county from 1950 to 2024[4]. FEMA rates tornado risk Relatively High compared with other US counties[16].
Is Boulder County at risk of wildfire?
FEMA rates wildfire risk Relatively High compared with other US counties, with a score of 97.8 out of 100[14]. OpenFEMA lists 9 fire declarations that include the county[2].
Is Boulder County at risk of hurricanes?
FEMA rates hurricane Not Applicable for the county[11].
How many disasters have been declared in Boulder County?
OpenFEMA lists 17 federal disaster declarations for natural hazards that include the county since 1969[2].

Facts and sources

  1. FEMA National Risk Index (version 1.20, December 2025): Expected Annual Loss from all 18 natural hazards in Boulder County is $125.3 million a year (Expected Annual Loss rating Relatively Moderate, score 92.6). Of this, buildings account for $100.8 million, injuries and deaths (converted to dollars by FEMA) for... FEMA National Risk Index
  2. OpenFEMA Disaster Declarations Summaries list 17 federal disaster declarations for natural hazards that include Boulder County since 1969 (6 major disaster, 11 emergency or fire management). By incident type: fire 9, flood 5, snowstorm 2, coastal storm 1. Biological (such as COVID-19) and other non-natural... OpenFEMA Disaster Declarations
  3. HazardFacts tally of OpenFEMA NFIP Redacted Claims (losses from 1978 to 2026): 1,784 National Flood Insurance Program claims were filed for losses in Boulder County, 1,375 of them with a payment, and NFIP paid $50.1 million in total (building, contents and increased cost of compliance, in dollars of the year paid).... OpenFEMA NFIP claims
  4. NOAA Storm Prediction Center tornado database (1950 to 2024): 11 recorded tornadoes touched Boulder County. The strongest were rated EF3 (most recent of them on 2015-06-04). 1 were rated F3/EF3 or stronger. The most recent recorded tornado was on 2015-06-04. Ratings used the Fujita scale until early 2007 and the... NOAA Storm Prediction Center
  5. FEMA National Risk Index (version 1.20, December 2025): the overall natural hazard Risk Index rating for Boulder County is Relatively Moderate, with a Risk Index score of 90.7 out of 100. The score is the county's percentile rank among all US counties. FEMA National Risk Index
  6. Among the 18 hazards in the FEMA National Risk Index (version 1.20, December 2025), the hazards with the highest hazard-type Risk Index scores for Boulder County are lightning (98.9, Very High), hail (98.4, Relatively High), wildfire (97.8, Relatively High). HazardFacts sorted FEMA's published scores; FEMA's scores... FEMA National Risk Index
  7. HazardFacts sorted FEMA's hazard-type Expected Annual Loss values for Boulder County (National Risk Index v1.20): the largest are inland flooding ($69.1 million a year), wildfire ($15.7 million a year), tornado ($12.4 million a year), out of $125.3 million a year from all 18 hazards. FEMA National Risk Index
  8. FEMA's National Risk Index FAQ (December 2025): Expected Annual Loss is FEMA's estimate of the average economic loss in dollars from natural hazards each year. The index is not meant to predict how much damage a community will have in the next year, and a hazard can still cause damage where a rating is low. Scores... FEMA National Risk Index documentation
  9. FEMA National Risk Index (version 1.20, December 2025): Social Vulnerability rating for Boulder County is Very Low (score 11.3). FEMA describes social vulnerability as how susceptible social groups are to the harm natural hazards cause. FEMA National Risk Index
  10. FEMA National Risk Index (version 1.20, December 2025): Community Resilience rating for Boulder County is Very High (score 91.2). FEMA describes community resilience as a community's ability to prepare for, withstand and recover from hazards. FEMA National Risk Index
  11. FEMA National Risk Index (version 1.20, December 2025) rates these hazards Not Applicable for Boulder County: coastal flooding, hurricane, tsunami. FEMA uses Not Applicable when its source data has no historical record of the hazard in the community and the hazard is not considered geographically possible there. FEMA National Risk Index documentation
  12. FEMA National Risk Index (version 1.20, December 2025), lightning in Boulder County: Risk Index rating Very High (score 98.9 of 100). Expected Annual Loss $5.9 million a year (rating Very High). Annualized frequency 54.13 events per year, from recorded occurrences over a period of record of 24 years. FEMA National Risk Index
  13. FEMA National Risk Index (version 1.20, December 2025), hail in Boulder County: Risk Index rating Relatively High (score 98.4 of 100). Expected Annual Loss $10.3 million a year (rating Relatively High). Annualized frequency 5.48 events per year, from recorded occurrences over a period of record of 37 years. FEMA National Risk Index
  14. FEMA National Risk Index (version 1.20, December 2025), wildfire in Boulder County: Risk Index rating Relatively High (score 97.8 of 100). Expected Annual Loss $15.7 million a year (rating Relatively High). FEMA's modeled annual frequency is 0.0057 events per year. FEMA National Risk Index
  15. FEMA National Risk Index (version 1.20, December 2025), winter weather in Boulder County: Risk Index rating Relatively High (score 96.0 of 100). Expected Annual Loss $1.1 million a year (rating Very High). Annualized frequency 21.4 events per year, from recorded occurrences over a period of record of 18 years. FEMA National Risk Index
  16. FEMA National Risk Index (version 1.20, December 2025), tornado in Boulder County: Risk Index rating Relatively High (score 92.5 of 100). Expected Annual Loss $12.4 million a year (rating Relatively High). Annualized frequency 0.52 events per year, from recorded occurrences over a period of record of 38 years. FEMA National Risk Index
  17. FEMA National Risk Index (version 1.20, December 2025), inland flooding in Boulder County: Risk Index rating Relatively Moderate (score 92.2 of 100). Expected Annual Loss $69.1 million a year (rating Relatively High). Annualized frequency 0.75 event-days per year, from recorded occurrences over a period of record... FEMA National Risk Index
  18. FEMA National Risk Index (version 1.20, December 2025), landslide in Boulder County: Risk Index rating Relatively Moderate (score 89.8 of 100). Expected Annual Loss $78,000 a year (rating Relatively Low). FEMA National Risk Index
  19. FEMA National Risk Index (version 1.20, December 2025), avalanche in Boulder County: Risk Index rating Relatively High (score 87.2 of 100). Expected Annual Loss $1.8 million a year (rating Relatively Moderate). Annualized frequency 0.63 events per year, from recorded occurrences over a period of record of 28 years. FEMA National Risk Index
  20. FEMA National Risk Index (version 1.20, December 2025), strong wind in Boulder County: Risk Index rating Relatively High (score 85.9 of 100). Expected Annual Loss $2.3 million a year (rating Relatively High). Annualized frequency 1 events per year, from recorded occurrences over a period of record of 38 years. FEMA National Risk Index
  21. FEMA National Risk Index (version 1.20, December 2025), earthquake in Boulder County: Risk Index rating Relatively Low (score 80.5 of 100). Expected Annual Loss $2.4 million a year (rating Relatively Low). FEMA's modeled annual frequency is 0.0008 events per year. FEMA National Risk Index
  22. FEMA National Risk Index (version 1.20, December 2025), ice storm in Boulder County: Risk Index rating Relatively Moderate (score 72.8 of 100). Expected Annual Loss $354,000 a year (rating Relatively Moderate). Annualized frequency 0.01 event-days per year, from recorded occurrences over a period of record of 68... FEMA National Risk Index
  23. FEMA National Risk Index (version 1.20, December 2025), cold wave in Boulder County: Risk Index rating Relatively Moderate (score 70.6 of 100). Expected Annual Loss $3.0 million a year (rating Relatively Moderate). Annualized frequency 0.59 event-days per year, from recorded occurrences over a period of record of... FEMA National Risk Index
  24. FEMA National Risk Index (version 1.20, December 2025), volcanic activity in Boulder County: Risk Index rating Very Low (score 64.8 of 100). Expected Annual Loss $79 a year (rating Very Low). FEMA National Risk Index
  25. FEMA National Risk Index (version 1.20, December 2025), heat wave in Boulder County: Risk Index rating Relatively Low (score 60.4 of 100). Expected Annual Loss $815,000 a year (rating Relatively Low). Annualized frequency 0.31 event-days per year, from recorded occurrences over a period of record of 18 years. FEMA National Risk Index
  26. FEMA National Risk Index (version 1.20, December 2025), drought in Boulder County: Risk Index rating Relatively Low (score 38.3 of 100). Expected Annual Loss $79,000 a year (rating Relatively Low). Annualized frequency 11.23 event-days per year, from recorded occurrences over a period of record of 22 years. FEMA National Risk Index
  27. NFIP Residential Penetration Rates (OpenFEMA, as of 2026-08-03): 2,543 residential flood insurance contracts were in force in Boulder County, out of 111,369 residential structures, a penetration rate of 2.3%. Inside FEMA's mapped Special Flood Hazard Area there were 2,870 residential structures and 1,276 contracts,... OpenFEMA NFIP penetration rates
  28. FEMA's Flood Map Service Center is the official public source for flood maps (Flood Insurance Rate Maps) produced under the National Flood Insurance Program. Flood zones apply to specific properties: look up an address there or ask the local floodplain manager. County-level ratings do not tell you the flood zone of... FEMA Flood Map Service Center
  29. Most recent federal disaster declarations for natural hazards (table on this page). OpenFEMA Disaster Declarations

FEMA's National Risk Index compares each county with all other US counties. Ratings are relative (Very Low to Very High), not a measure of safety. Never call a place safe, unsafe, good or bad to live in. Risk Index and Expected Annual Loss values are FEMA estimates for planning. They do not predict next year's losses and do not apply to a single property. Flood zones are set by FEMA flood maps for specific properties. County ratings and flood insurance counts do not tell anyone whether an address is in a flood zone. Disaster declaration, NFIP and tornado counts are records of the past for this county only. Do not compare with other counties unless a fact does.

Federal Emergency Management Agency (FEMA), National Risk Index Dataset: National Risk Index Counties, v1.20 (December 2025). Retrieved from fema.maps.arcgis.com on October 30, 2026. This product uses the Federal Emergency Management Agency's National Risk Index dataset API or downloadable datasets but is not endorsed by FEMA. The Federal Government or FEMA cannot vouch for the data or analyses derived from these data after the data have been retrieved from the Agency's website(s). This product uses the FEMA OpenFEMA API, but is not endorsed by FEMA.