Cowlitz County, Washington Natural Disaster Risk
FEMA National Risk Index assessment · WA
MediumComposite Risk Score
National percentile: 90th
Cowlitz County faces medium composite natural disaster risk (NRI Risk Index score 90.3, 90th national percentile), driven primarily by volcanic activity and earthquake exposure. Expected annual loss across all 18 hazard types is $88M.
Source: FEMA National Risk Index v1.20 · Updated December 2025
Risk Overview
Overall natural disaster risk in Cowlitz County is medium, with a National Risk Index score of 90.3 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.
The county's risk is driven primarily by volcanic activity (eruptions producing ashfall, lava, and pyroclastic hazards) at High risk — $8M in expected annual loss and about 0.01 events per year; earthquake (ground shaking from sudden movement along geologic faults) at Medium risk — $39M in expected annual loss and about 0.02 events per year; and heat wave (prolonged periods of extreme heat that threaten health and infrastructure) at Medium risk — $4M in expected annual loss and about 5.00 events per year. Across all hazards, FEMA estimates $88M in expected annual loss for a population of 111K.
Beyond physical exposure, Cowlitz County has a 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.
History supports the rating: Cowlitz County has received 23 federal disaster declarations since 1964, including 11 for flood events and 6 for severe storm events. The most recent was Severe Storms, Straight-Line Winds, Flooding, Landslides, and Mudslides (flood), declared in April 2026.
Among 39 Washington counties, Cowlitz County ranks #12 for overall natural disaster risk.
Top Hazards
All 18 Hazard Risks
| Volcanic Activity | High | 0.01 / yr | $8M |
| Earthquake | Medium | 0.02 / yr | $39M |
| Heat Wave | Medium | 5.00 / yr | $4M |
| Riverine Flood | Medium | 0.75 / yr | $34M |
| Landslide | Low | 2.30 / yr | $26K |
| Cold Wave | Medium | 0.27 / yr | $3M |
| Wildfire | Very Low | 0.00 / yr | $94K |
| Coastal Flood | Low | 1.62 / yr | $152K |
| Winter Weather | Low | 21.10 / yr | $65K |
| Strong Wind | Low | 0.04 / yr | $400K |
| Ice Storm | Low | 0.33 / yr | $35K |
| Avalanche | Very Low | 0.01 / yr | $56 |
| Lightning | Very Low | 6.13 / yr | $80K |
| Tornado | Very Low | 0.09 / yr | $252K |
| Hail | Very Low | 0.05 / yr | $43K |
| Drought | Very Low | 0.00 / yr | $0 |
| Hurricane | Very Low | 0.00 / yr | $0 |
| Tsunami | Very Low | 0.00 / yr | $0 |
Disaster History
Cowlitz County has received 23 federal disaster declarations since 1964, most recently Severe Storms, Straight-Line Winds, Flooding, Landslides, and Mudslides in April 2026. Most frequent causes: Flood (11), Severe Storm (6), Biological (2).
| Declared | Type | Disaster |
|---|---|---|
| April 2026 | Flood | Severe Storms, Straight-Line Winds, Flooding, Landslides, and Mudslides |
| April 2024 | Severe Storm | Severe Winter Storms, Straight-Line Winds, Flooding, Landslides, and Mudslides |
| March 2022 | Flood | Severe Winter Storms, Snowstorms, Straight-Line Winds, Flooding |
| 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 |
| February 2016 | Flood | Severe Winter Storm, Straight-Line Winds, Flooding, Landslides, Mudslides, and a T |
| March 2009 | Severe Storm | Severe Winter Storm and Record and Near Record Snow |
| January 2009 | Flood | Severe Winter Storm, Landslides, Mudslides, and Flooding |
| December 2006 | Severe Storm | Severe Storms, Flooding, Landslides, and Mudslides |
Showing the 10 most recent of 23 declarations.
Source: FEMA Disaster Declarations Summaries (OpenFEMA).
Frequently Asked Questions
What is the overall natural disaster risk for Cowlitz County?
Cowlitz County has a composite FEMA National Risk Index score of 90.3 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 Cowlitz County?
The three highest-rated hazards are Volcanic Activity (High, $8M EAL), Earthquake (Medium, $39M EAL), Heat Wave (Medium, $4M EAL). These account for most of the county's expected annual losses.
How does Cowlitz County compare to other Washington counties?
Cowlitz County ranks #12 of 39 Washington counties for overall natural disaster risk, with a medium rating.
How many federally declared disasters has Cowlitz County had?
FEMA records 23 federal disaster declarations for Cowlitz County since 1964, most often 11 for flood events and 6 for severe storm 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. Cowlitz County's $88M EAL is a statistical average, not a guarantee for any specific year or address.