Canyon County, Idaho Natural Disaster Risk
FEMA National Risk Index assessment · ID
LowComposite Risk Score
National percentile: 72th
Canyon County faces low composite natural disaster risk (NRI Risk Index score 71.7, 72th national percentile), driven primarily by winter weather and wildfire exposure. Expected annual loss across all 18 hazard types is $36M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
FEMA's National Risk Index rates Canyon County at low composite risk, with a National Risk Index score of 71.7 out of 100 — placing it in the 72nd national percentile and below the national average for natural-disaster risk. The score blends Expected Annual Loss, Social Vulnerability, and Community Resilience across all 18 FEMA hazard types.
Most of Canyon County's expected losses come from winter weather (heavy snow, blizzards, and hazardous winter conditions) at Very High risk — $1M in expected annual loss and about 8.26 events per year; wildfire (uncontrolled fires that spread across wildland and into communities) at Medium risk — $2M in expected annual loss and about 0.00 events per year; and heat wave (prolonged periods of extreme heat that threaten health and infrastructure) at Medium risk — $3M in expected annual loss and about 4.53 events per year. Across all hazards, FEMA estimates $36M in expected annual loss for a population of 231K.
Beyond physical exposure, Canyon County has a very low social vulnerability rating (how susceptible the population is to harm) and a medium community resilience rating (its capacity to prepare for and recover from disasters). Both measures sit toward the lower end, indicating relatively modest population sensitivity.
The county's disaster history tells the same story: Canyon County has received 4 federal disaster declarations since 2005, including 2 for biological events and 1 for flood events. The most recent was Covid-19 Pandemic (biological), declared in April 2020.
Among 44 Idaho counties, Canyon County ranks #6 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Winter Weather | Very High | 8.26 / yr | $1M |
| Wildfire | Medium | 0.00 / yr | $2M |
| Heat Wave | Medium | 4.53 / yr | $3M |
| Lightning | High | 17.83 / yr | $1M |
| Riverine Flood | Medium | 0.39 / yr | $24M |
| Earthquake | Low | 0.00 / yr | $2M |
| Ice Storm | Medium | 0.09 / yr | $323K |
| Volcanic Activity | Very Low | 0.00 / yr | $110 |
| Strong Wind | Medium | 0.34 / yr | $1M |
| Hail | Low | 0.25 / yr | $273K |
| Landslide | Very Low | 0.06 / yr | $420 |
| Cold Wave | Low | 0.05 / yr | $414K |
| Drought | Very Low | 17.43 / yr | $6K |
| Tornado | Very Low | 0.03 / yr | $300K |
| Avalanche | Very Low | 0.01 / yr | $3 |
| Coastal Flood | Very Low | 0.00 / yr | $0 |
| Hurricane | Very Low | 0.00 / yr | $0 |
| Tsunami | Very Low | 0.00 / yr | $0 |
Disaster History
Canyon County has received 4 federal disaster declarations since 2005, most recently Covid-19 Pandemic in April 2020. Most frequent causes: Biological (2), Flood (1), Hurricane (1).
| Declared | Type | Disaster |
|---|---|---|
| April 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| October 2017 | Flood | Flooding |
| September 2005 | Hurricane | Hurricane Katrina |
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Canyon County?
Canyon County has a composite FEMA National Risk Index score of 71.7 out of 100, placing it in the Low category and the 72th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Canyon County?
The three highest-rated hazards are Winter Weather (Very High, $1M EAL), Wildfire (Medium, $2M EAL), Heat Wave (Medium, $3M EAL). These account for most of the county's expected annual losses.
How does Canyon County compare to other Idaho counties?
Canyon County ranks #6 of 44 Idaho counties for overall natural disaster risk, with a low rating.
How many federally declared disasters has Canyon County had?
FEMA records 4 federal disaster declarations for Canyon County since 2005, most often 2 for biological events and 1 for flood events. The most recent was Covid-19 Pandemic, declared in April 2020.
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. Canyon County's $36M EAL is a statistical average, not a guarantee for any specific year or address.