Ada County, ID
FEMA National Risk Index scores, disaster declarations & hazard data
Ada County has experienced 6 federally declared disasters since 1965, most recently Covid-19 in 2020. Its overall natural hazard risk is rated Relatively Moderate — near the middle compared to other US counties.
Ada County's highest-rated hazards are winter weather, wildfire, and heat wave, with its top risk rated "Very High" by FEMA's National Risk Index. NOAA records 21 storm events in the county over the past decade. Community vulnerability is relatively low (19th percentile nationally), indicating stronger recovery capacity than most US counties.
Past disasters & FEMA designations
A federal disaster declaration officially designates a county for FEMA disaster assistance. Ada County has been designated in 6 declarations since 1965, covering 4 disaster types including biological (2), flood (2), hurricane (1).
| Year | Type | Event name |
|---|---|---|
| 2020 | Biological | Covid-19 Pandemic |
| 2020 | Biological | Covid-19 |
| 2018 | Flood | Flooding |
| 2005 | Hurricane | Hurricane Katrina |
| 2000 | Fire | Wildfires |
| 1965 | Flood | Heavy Rains & Flooding |
Source: FEMA OpenFEMA Disaster Declarations Summaries. A single disaster can produce more than one record per county. Data current through September 2026.
Risk by hazard type
| Hazard | Risk rating | Risk score | Recorded events | Deaths | Prop. damage |
|---|---|---|---|---|---|
| Wildfire | Relatively High | 98.3 | 0 | 0 | — |
| Inland Flooding | Relatively Moderate | 89.8 | 11 | 0 | $5.0M |
| Coastal Flooding | Not Applicable | — | 0 | 0 | — |
| Earthquake | Relatively Low | 88.2 | — | — | — |
| Heat Wave | Relatively Moderate | 92.9 | 0 | 0 | — |
| Tornado | Relatively Low | 27 | 1 | 0 | — |
| Hurricane | Not Applicable | — | 0 | 0 | — |
| Hail | Relatively Low | 54.5 | 6 | 0 | — |
| Strong Wind | Relatively High | 91.8 | 0 | 0 | — |
| Winter Weather | Very High | 98.9 | 0 | 0 | — |
| Ice Storm | Relatively Moderate | 80.5 | — | — | — |
| Cold Wave | Relatively Low | 51.7 | — | — | — |
| Lightning | Relatively High | 90.1 | 0 | 0 | — |
| Drought | Very Low | 14.6 | 0 | 0 | — |
| Landslide | Relatively Low | 69.1 | 3 | 0 | — |
| Avalanche | Very Low | 27 | — | — | — |
| Tsunami | Not Applicable | — | — | — | — |
| Volcanic Activity | Very Low | 74.3 | — | — | — |
Scores are 0–100 percentiles relative to all US counties — higher means more exposed, not that a disaster is likely this year. Event counts: NOAA Storm Events 2016–2026; earthquake counts from USGS ComCat (M3.0+, 1996–2026). See the methodology page for details.
Community vulnerability
Ada County ranks in the 19th percentile (Very low) for community vulnerability — a measure of how hard disaster impacts tend to hit residents. Higher vulnerability means more displacement, worse health outcomes, and slower recovery after a disaster.
| SVI theme | Percentile | Vulnerability level |
|---|---|---|
| Overall | 19th | Very low |
| Socioeconomic status | 16th | Very low |
| Household characteristics | 16th | Very low |
| Racial & ethnic minority status | 48th | Low |
| Housing type & transportation | 38th | Low |
Source: CDC/ATSDR Social Vulnerability Index 2022. Percentiles compare counties nationally — higher means more vulnerable relative to other counties. See CDC SVI for full methodology.
Future risk outlook
| Wildfire metric | National percentile | Level |
|---|---|---|
| Burn probability | 99th | Very High |
| Risk to homes | 99th | Very High |
| Buildings in direct exposure zone | 26.9% | — |
NOAA tracked 21 weather events in this county over 2016–2025: 7 in 2016–20 vs 14 in 2021–25 .
Wildfire: USDA Forest Service Wildfire Risk to Communities (RDS-2020-0016-2) — modeled values, not annual forecasts. See wildfirerisk.org. Inland flood and heat projections pending data availability; coastal sea-level projections are available for select coastal counties below — see the data page.
Nearby counties
Frequently asked questions
What natural hazards pose the greatest risk in Ada County?
According to the FEMA National Risk Index, the highest-risk hazards in Ada County, Idaho are winter weather, wildfire, and heat wave. The county's overall natural hazard risk is rated Relatively Moderate — near the middle compared to other US counties.
Has Ada County received federal disaster declarations?
Yes. Ada County has received 6 federal disaster declarations since 1965, including declarations in 2020. The most common disaster type on record is biological (2 declarations).
Has Ada County had any FEMA disaster declarations in 2024, 2025, or 2026?
No federal disaster declarations have been recorded for Ada County since the start of 2024. Its most recent declaration on record is Covid-19 in 2020.
How does Ada County's natural hazard risk compare to nearby counties?
Among neighboring counties, Canyon County, ID has the highest overall natural hazard risk (Relatively Low) and Payette County, ID has the lowest (Very Low). Ada County is rated Relatively Moderate overall.
How is Ada County's composite disaster risk index calculated?
Ada County's composite disaster risk index — officially FEMA's National Risk Index (NRI) — scores every US county on a 0–100 percentile scale across 18 natural hazard types, factoring in expected annual loss, social vulnerability, and community resilience. Ada County's composite score of 88 means its overall natural hazard risk is higher than 88% of US counties.