Larimer County, Colorado Natural Disaster Risk
FEMA National Risk Index assessment · CO
MediumComposite Risk Score
National percentile: 90th
Larimer County faces medium composite natural disaster risk (NRI Risk Index score 90.1, 90th national percentile), driven primarily by lightning and hail exposure. Expected annual loss across all 18 hazard types is $127M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
Overall natural disaster risk in Larimer County is medium, with a National Risk Index score of 90.1 out of 100 — placing it in the 90th national percentile and near the national midpoint for natural-disaster risk. The score blends Expected Annual Loss, Social Vulnerability, and Community Resilience across all 18 FEMA hazard types.
Risk here concentrates in lightning (electrical discharges from storms that ignite fires and cause casualties) at Very High risk — $7M in expected annual loss and about 56.90 events per year; hail (ice stones from severe thunderstorms that damage property and crops) at High risk — $11M in expected annual loss and about 4.38 events per year; and winter weather (heavy snow, blizzards, and hazardous winter conditions) at Very High risk — $2M in expected annual loss and about 22.30 events per year. Across all hazards, FEMA estimates $127M in expected annual loss for a population of 359K.
Beyond physical exposure, Larimer County has a very low social vulnerability rating (how susceptible the population is to harm) and a high community resilience rating (its capacity to prepare for and recover from disasters). A less vulnerable population paired with strong resilience helps the community absorb and recover from events.
History supports the rating: Larimer County has received 30 federal disaster declarations since 1965, including 15 for fire events and 7 for flood events. The most recent was Alexander Mountain Fire (fire), declared in July 2024.
Among 64 Colorado counties, Larimer County ranks #7 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Lightning | Very High | 56.90 / yr | $7M |
| Hail | High | 4.38 / yr | $11M |
| Winter Weather | Very High | 22.30 / yr | $2M |
| Wildfire | High | 0.00 / yr | $15M |
| Landslide | Medium | 1.14 / yr | $491K |
| Cold Wave | High | 0.56 / yr | $16M |
| Avalanche | High | 0.20 / yr | $3M |
| Tornado | High | 1.30 / yr | $11M |
| Riverine Flood | Medium | 2.07 / yr | $54M |
| Strong Wind | High | 0.88 / yr | $3M |
| Earthquake | Low | 0.00 / yr | $3M |
| Volcanic Activity | Very Low | 0.00 / yr | $69 |
| Heat Wave | Low | 0.18 / yr | $817K |
| Ice Storm | Low | 0.02 / yr | $132K |
| Drought | Low | 18.06 / yr | $182K |
| Coastal Flood | Very Low | 0.00 / yr | $0 |
| Hurricane | Very Low | 0.00 / yr | $0 |
| Tsunami | Very Low | 0.00 / yr | $0 |
Disaster History
Larimer County has received 30 federal disaster declarations since 1965, most recently Alexander Mountain Fire in July 2024. Most frequent causes: Fire (15), Flood (7), Biological (2).
| Declared | Type | Disaster |
|---|---|---|
| July 2024 | Fire | Alexander Mountain Fire |
| July 2024 | Fire | Stone Mountain Fire |
| January 2021 | Fire | Wildfires |
| September 2020 | Fire | Cameron Peak Fire |
| March 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| September 2013 | Flood | Severe Storms, Flooding, Landslides, and Mudslides |
| September 2013 | Flood | Severe Storms, Flooding, Landslides, and Mudslides |
| June 2012 | Fire | High Park and Waldo Canyon Wildfires |
| June 2012 | Fire | High Park Fire |
Showing the 10 most recent of 30 declarations.
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Larimer County?
Larimer County has a composite FEMA National Risk Index score of 90.1 out of 100, placing it in the Medium category and the 90th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Larimer County?
The three highest-rated hazards are Lightning (Very High, $7M EAL), Hail (High, $11M EAL), Winter Weather (Very High, $2M EAL). These account for most of the county's expected annual losses.
How does Larimer County compare to other Colorado counties?
Larimer County ranks #7 of 64 Colorado counties for overall natural disaster risk, with a medium rating.
How many federally declared disasters has Larimer County had?
FEMA records 30 federal disaster declarations for Larimer County since 1965, most often 15 for fire events and 7 for flood events. The most recent was Alexander Mountain Fire, declared in July 2024.
What does Expected Annual Loss (EAL) mean?
EAL is FEMA's estimate of average annual dollar losses from natural hazards, calculated from historical event data and exposure models. Larimer County's $127M EAL is a statistical average, not a guarantee for any specific year or address.