Boulder County, Colorado: Natural Disaster Risk and History
Boulder County, Colorado has a Relatively Moderate natural-hazard risk rating in FEMA's National Risk Index (v1.20, December 2025): a score of 90.7 out of 100, higher than about 90% of US counties, with lightning, hail and wildfires scoring highest of its 18 hazards and $125 million a year in expected losses.
OpenFEMA lists 17 federal disaster declarations that included Boulder County since 1969, not counting 2 for COVID-19; the latest is FM-5525-CO (Stone Mountain Fire, declared 31 July 2024). NOAA's Storm Prediction Center recorded 11 tornadoes touching Boulder County from 1950 to 2025.
Live weather alerts for Colorado All official warnings Latest FEMA declarations
Population 330,652 Buildings worth $70 billion Area 748 sq mi Risk rank in Colorado 6 of 64 FIPS 08013
All 18 hazards, highest risk first
FEMA National Risk Index| Hazard | Risk rating | Score | Expected loss a year | How often | Events in record |
|---|---|---|---|---|---|
| Lightning | Very High | 99.0 | $5.9 million | about 54 a year | 299,770 strikes |
| Hail | Relatively High | 98.4 | $10 million | about 5.5 a year | 209 |
| Wildfire | Relatively High | 97.9 | $16 million | about once every 175 years | — |
| Winter weather | Relatively High | 96.1 | $1.1 million | about 21 a year | 406 |
| Tornado | Relatively High | 92.6 | $12 million | about once every 1.9 years | 6 |
| Inland flooding | Relatively Moderate | 92.2 | $69 million | about once every 1.3 years | 21 |
| Landslide | Relatively Moderate | 89.9 | $77,916 | about once every 3.7 years | — |
| Avalanche | Relatively High | 87.3 | $1.8 million | about once every 1.6 years | 19 |
| Strong wind | Relatively High | 86.0 | $2.3 million | about once a year | 38 |
| Earthquake | Relatively Low | 80.5 | $2.4 million | rarer than once in 1,000 years | — |
| Ice storm | Relatively Moderate | 72.9 | $354,171 | about once every 67 years | 0 |
| Cold wave | Relatively Moderate | 70.6 | $3.0 million | about once every 1.7 years | 11 |
| Volcanic activity | Very Low | 64.8 | $79 | rarer than once in 1,000 years | 1 |
| Heat wave | Relatively Low | 60.4 | $814,876 | about once every 3.3 years | 3.9 |
| Drought | Relatively Low | 38.4 | $79,345 | about 11 a year | 441 |
| Coastal flooding | Not Applicable | — | — | — | — |
| Hurricane | Not Applicable | — | — | — | — |
| Tsunami | Not Applicable | — | — | — | — |
Score: FEMA's percentile among US counties that face the hazard (higher = more risk). Expected loss: FEMA's modelled average yearly loss to buildings, people (as a statistical value) and crops. How often: FEMA's annualised frequency of the hazard in the county; for some hazards it counts event-days, so it is a rough guide, not a forecast. "Not Applicable" means FEMA does not model that hazard here.
Federal disaster declarations 17
Most common: Fire 9, Flood 5, Snowstorm 2, Coastal Storm 1.
| Decade | Declarations | Incident types |
|---|---|---|
| 1960s | 1 | Flood |
| 1970s | 1 | Flood |
| 2000s | 7 | Fire ×4, Snowstorm ×2, Coastal Storm |
| 2010s | 4 | Flood ×3, Fire |
| 2020s | 4 | Fire ×4 |
The last 10
Widest declarations that included Boulder County
- Hurricane Katrina Evacuation (2005, EM-3224-CO): 64 Colorado counties designated.
- Wildfires (2002, DR-1421-CO): 58 Colorado counties designated.
- Snow (2003, EM-3185-CO): 29 Colorado counties designated.
Named storms in its declarations: Hurricane Katrina (2005).
Not counted above: 2 COVID-19 ("Biological") declarations — in 2020 every US county was included. Colorado also had 12 statewide declarations with no county list.
Tornado record since 1950 11
| Tornadoes touching the county | 11 |
|---|---|
| Strongest-rated | (E)F3 ×1 |
| Peak month | June (5) |
| Deadliest | — |
| Longest path | 4 Jun 2015, EF3, 6.7 mi path |
| Most recent | 4 Jun 2015, EF3, 6.7 mi path |
| Deaths / injuries on those paths | 0 / 0 |
| Rating | (E)F0 | (E)F1 | (E)F2 | (E)F3 | (E)F4 | (E)F5 | Unrated |
|---|---|---|---|---|---|---|---|
| Count | 2 | 6 | 2 | 1 | 0 | 0 | 0 |
| Decade | 1950s | 1960s | 1970s | 1980s | 1990s | 2000s | 2010s | 2020s |
|---|---|---|---|---|---|---|---|---|
| Count | 2 | 0 | 1 | 3 | 4 | 0 | 1 | 0 |
Deaths and injuries are for each tornado's whole path, which can run beyond this county. F-scale ratings before February 2007, Enhanced Fujita (EF) after.
How Boulder County compares with its 5 nearest counties
| County | Distance | Overall risk | Score | Top hazard |
|---|---|---|---|---|
| Boulder County (this page) | — | Relatively Moderate | 90.7 | Lightning |
| Gilpin County | 30 km | Very Low | 6.4 | Wildfire |
| Broomfield County | 30 km | Very Low | 34.7 | Hail |
| Clear Creek County | 51 km | Relatively Low | 46.7 | Avalanche |
| Denver County | 55 km | Relatively High | 95.2 | Hail |
| Jefferson County | 57 km | Relatively High | 94.9 | Hail |
Nearest by distance between county centres. Every county in Colorado, ranked.
Vulnerability and resilience
| Social vulnerability | Very Low 11.4 |
|---|---|
| Community resilience | Very High 91.2 |
| Community risk factor | 0.76 |
| Expected annual loss, all hazards | $125 million |
FEMA scales expected losses up where social vulnerability is high (people who may find it harder to prepare, evacuate or recover) and down where community resilience is high. A factor above 1 raises the risk score. For social vulnerability a high rating is worse; for resilience a high rating is better.
Prepare for Boulder County's main hazards
- Right now: National Weather Service alerts for Colorado · all official warnings on Global Incident Tracker.
- Lightning: Weather alerts for Colorado
- Hail: Weather alerts for Colorado
- Wildfire: US wildfires now · Wildfire smoke: what protects you
- Your property's flood zone: FEMA Flood Map Service Center ↗ — this page cannot tell you that.
- Official preparedness guidance: Ready.gov ↗ and your county emergency management office.
What this page shows, and what it misses
FEMA's National Risk Index rates a whole county against every other US county; it is a planning-level estimate for nationwide comparison, not a flood-zone map and not a substitute for a local risk assessment or the risk to one home. Declarations are presidential disaster, emergency and fire management declarations that named this county; state declarations and SBA or USDA designations are not included. Tornadoes are counted when the county is one of up to four listed on the track; 670 tornadoes that crossed a state line carry no county list in NOAA's file and are left out.
Federal Emergency Management Agency (FEMA), National Risk Index Dataset: National Risk Index Counties - v1.20.0 (December 2025). Retrieved from https://services.arcgis.com/XG15cJAlne2vxtgt/ArcGIS/rest/services/National_Risk_Index_Counties/FeatureServer/0/query on November 2, 2026, 1:20 PM EST. 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).
Federal Emergency Management Agency (FEMA), OpenFEMA Dataset: Disaster Declarations Summaries - v2, retrieved from https://www.fema.gov/api/open/v2/DisasterDeclarationsSummaries on November 2, 2026, 1:21 PM EST. This product uses the Federal Emergency Management Agency's OpenFEMA API, 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).
Tornado records: NOAA/NWS Storm Prediction Center, Severe Weather Database, tornadoes 1950–2025 (https://www.spc.noaa.gov/wcm/data/1950-2025_actual_tornadoes.csv, downloaded 2 November 2026). Public domain; not endorsed by NOAA. Compiled by Global Incident Tracker.
Questions about Boulder County
What natural disasters is Boulder County, Colorado most at risk from?
Boulder County, Colorado has a Relatively Moderate natural-hazard risk rating in FEMA's National Risk Index (v1.20, December 2025): a score of 90.7 out of 100, higher than about 90% of US counties, with lightning, hail and wildfires scoring highest of its 18 hazards and $125 million a year in expected losses.
How many federal disaster declarations has Boulder County had?
OpenFEMA lists 17 federal disaster declarations that included Boulder County since 1969, not counting 2 for COVID-19; the latest is FM-5525-CO (Stone Mountain Fire, declared 31 July 2024). Another 12 Colorado declarations were made statewide without a county list.
How many tornadoes have hit Boulder County?
NOAA's Storm Prediction Center recorded 11 tornadoes touching Boulder County from 1950 to 2025.
Is the National Risk Index a flood zone map?
No. The National Risk Index is a planning-level estimate for a whole county, built for nationwide comparison. It does not tell you the flood zone or the risk of a single property: for that, look up the address on FEMA's Flood Map Service Center (msc.fema.gov) and ask your local floodplain manager.