Volcanic Activity Risk in Washington
All Washington counties ranked by FEMA National Risk Index volcanic activity score
Volcanic Activity risk — eruptions producing ashfall, lava, and pyroclastic hazards — is rated for 29 of 39 Washington counties in FEMA's National Risk Index. Cowlitz County carries the state's highest volcanic activity score at 99.7, with $8M in expected annual volcanic activity losses.
5 Washington counties are rated High or Very High for volcanic activity, and expected annual losses from volcanic activity total roughly $23M statewide. The full ranking below links to each county's complete 18-hazard risk profile.
County Rankings — Volcanic Activity
| # | County | Volcanic Activity Score | Rating | Ann. Freq. | Ann. Loss |
|---|---|---|---|---|---|
| 1 | Cowlitz County | High | 0.01 / yr | $8M | |
| 2 | Pierce County | High | 0.01 / yr | $7M | |
| 3 | Skagit County | High | 0.00 / yr | $3M | |
| 4 | King County | High | 0.01 / yr | $2M | |
| 5 | Skamania County | High | 0.01 / yr | $2M | |
| 6 | Snohomish County | Medium | 0.01 / yr | $675K | |
| 7 | Lewis County | Medium | 0.01 / yr | $287K | |
| 8 | Thurston County | Medium | 0.01 / yr | $195K | |
| 9 | Whatcom County | Medium | 0.00 / yr | $128K | |
| 10 | Klickitat County | Low | 0.01 / yr | $31K | |
| 11 | Chelan County | Low | 0.01 / yr | $15K | |
| 12 | Clark County | Low | 0.01 / yr | $15K | |
| 13 | Yakima County | Low | 0.01 / yr | $8K | |
| 14 | Island County | Low | 0.00 / yr | $3K | |
| 15 | Douglas County | Very Low | 0.01 / yr | $1K | |
| 16 | Kittitas County | Very Low | 0.01 / yr | $1K | |
| 17 | Grant County | Very Low | 0.01 / yr | $991 | |
| 18 | Benton County | Very Low | 0.01 / yr | $856 | |
| 19 | Okanogan County | Very Low | 0.00 / yr | $166 | |
| 20 | Franklin County | Very Low | 0.00 / yr | $207 | |
| 21 | Wahkiakum County | Very Low | 0.01 / yr | $81 | |
| 22 | Kitsap County | Very Low | 0.00 / yr | $117 | |
| 23 | Ferry County | Very Low | 0.00 / yr | $11 | |
| 24 | Mason County | Very Low | 0.00 / yr | $8 | |
| 25 | Adams County | Very Low | 0.00 / yr | $8 | |
| 26 | San Juan County | Very Low | 0.00 / yr | $4 | |
| 27 | Lincoln County | Very Low | 0.00 / yr | $0 | |
| 28 | Jefferson County | Very Low | 0.00 / yr | $0 | |
| 29 | Pacific County | Very Low | 0.01 / yr | $0 |
29 Washington counties with measurable volcanic activity risk. See the national volcanic activity ranking or all Washington counties by overall risk.
Frequently Asked Questions
Which Washington county has the highest volcanic activity risk?
Cowlitz County has the highest FEMA volcanic activity risk score in Washington at 99.7 (High), with $8M in expected annual losses and about 0.01 events per year.
How many Washington counties face significant volcanic activity risk?
29 Washington counties record measurable volcanic activity risk in FEMA's National Risk Index; 5 of them are rated High or Very High.