Jefferson County, Washington Natural Disaster Risk
FEMA National Risk Index assessment · WA
LowComposite Risk Score
National percentile: 64th
Jefferson County faces low composite natural disaster risk (NRI Risk Index score 64.4, 64th national percentile), driven primarily by landslide and earthquake exposure. Expected annual loss across all 18 hazard types is $17M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
Jefferson County carries a low composite natural disaster risk, with a National Risk Index score of 64.4 out of 100 — placing it in the 64th 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.
The county's risk is driven primarily by landslide (downhill movement of rock, soil, and debris on unstable slopes) at Medium risk — $123K in expected annual loss and about 17.00 events per year; earthquake (ground shaking from sudden movement along geologic faults) at Medium risk — $10M in expected annual loss and about 0.03 events per year; and winter weather (heavy snow, blizzards, and hazardous winter conditions) at Medium risk — $162K in expected annual loss and about 15.96 events per year. Across all hazards, FEMA estimates $17M in expected annual loss for a population of 33K.
Beyond physical exposure, Jefferson County has a very high 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). Higher vulnerability is partly offset by strong community resilience and recovery capacity.
The federal record bears this out: Jefferson County has received 30 federal disaster declarations since 1979, including 13 for severe storm events and 11 for flood events. The most recent was Severe Storms, Straight-Line Winds, Flooding, Landslides, and Mudslides (flood), declared in April 2026.
Among 39 Washington counties, Jefferson County ranks #26 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Landslide | Medium | 17.00 / yr | $123K |
| Earthquake | Medium | 0.03 / yr | $10M |
| Winter Weather | Medium | 15.96 / yr | $162K |
| Ice Storm | Medium | 0.19 / yr | $189K |
| Coastal Flood | Medium | 3.38 / yr | $515K |
| Avalanche | Very Low | 0.01 / yr | $888 |
| Riverine Flood | Low | 0.14 / yr | $5M |
| Tsunami | Very Low | 0.13 / yr | $287K |
| Heat Wave | Very Low | 1.40 / yr | $124K |
| Cold Wave | Low | 0.03 / yr | $220K |
| Wildfire | Very Low | 0.00 / yr | $7K |
| Drought | Very Low | 1.30 / yr | $2 |
| Volcanic Activity | Very Low | 0.00 / yr | $0 |
| Tornado | Very Low | 0.04 / yr | $41K |
| Lightning | Very Low | 3.99 / yr | $14K |
| Strong Wind | Very Low | 0.00 / yr | $6K |
| Hail | Very Low | 0.00 / yr | $1K |
| Hurricane | Very Low | 0.00 / yr | $0 |
Disaster History
Jefferson County has received 30 federal disaster declarations since 1979, most recently Severe Storms, Straight-Line Winds, Flooding, Landslides, and Mudslides in April 2026. Most frequent causes: Severe Storm (13), Flood (11), Biological (2).
| Declared | Type | Disaster |
|---|---|---|
| April 2026 | Flood | Severe Storms, Straight-Line Winds, Flooding, Landslides, and Mudslides |
| December 2025 | Flood | Severe Storms, Straight-Line Winds, Flooding, Landslides, and Mudslides |
| April 2024 | Severe Storm | Severe Winter Storms, Straight-Line Winds, Flooding, Landslides, and Mudslides |
| January 2023 | Severe Storm | Severe Winter Storm, Straight-Line Winds, Flooding, Landslides, and Mudslides |
| March 2022 | Flood | Severe Winter Storms, Snowstorms, Straight-Line Winds, Flooding |
| January 2022 | Flood | Severe Storms, Straight-Line Winds, Flooding, Landslides, and Mudslides |
| April 2021 | Severe Storm | Severe Winter Storm, Straight-Line Winds, Flooding, Landslides, and Mudslides |
| March 2020 | Biological | Covid-19 Pandemic |
| March 2020 | Biological | Covid-19 |
| March 2019 | Severe Storm | Severe Winter Storms, Straight-Line Winds, Flooding, Landslides, Mudslides, Tornado |
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 Jefferson County?
Jefferson County has a composite FEMA National Risk Index score of 64.4 out of 100, placing it in the Low category and the 64th national percentile. This combines Expected Annual Loss, Social Vulnerability, and Community Resilience across 18 hazard types.
What are the top natural hazards in Jefferson County?
The three highest-rated hazards are Landslide (Medium, $123K EAL), Earthquake (Medium, $10M EAL), Winter Weather (Medium, $162K EAL). These account for most of the county's expected annual losses.
How does Jefferson County compare to other Washington counties?
Jefferson County ranks #26 of 39 Washington counties for overall natural disaster risk, with a low rating.
How many federally declared disasters has Jefferson County had?
FEMA records 30 federal disaster declarations for Jefferson County since 1979, most often 13 for severe storm events and 11 for flood events. The most recent was Severe Storms, Straight-Line Winds, Flooding, Landslides, and Mudslides, declared in April 2026.
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. Jefferson County's $17M EAL is a statistical average, not a guarantee for any specific year or address.