Moderate Risk Washington  ·  Earthquake / Volcanic

Lewis County WA

EMERGENCY PREPAREDNESS & DISASTER RISK PROFILE  ·  LAST UPDATED: Mar 2026

6/ 10
Threat Score
Population
78
Area
2,436
sq miles
Primary Hazard
Earthquake / Volcanic
FEMA Disasters
7
federally declared

Lewis County WA in Washington faces earthquake / volcanic risk across its 2,436 square mile area. Chehalis in Mt. St. Helens lahar path faces Cascadia earthquake and flooding from Chehalis River. Lewis serves as the county seat and regional emergency coordination hub.

// Recommended Supplies

Essential gear for power outages, severe weather, and emergency situations in your area.

// Risk Intelligence

Threat Score 6 / 10    Moderate Risk
Primary Hazard Earthquake / Volcanic
Secondary Hazard Wildfire
FEMA Flood Zone Moderate
Federally Declared Disasters 7
Last Major Event Mt. St. Helens 1980
Event Frequency Annual

// Emergency Operations

Emergency Mgmt Phone (360) 740-1394
Emergency Shelters 3 designated facilities
Evacuation Routes State and US highways

// County Profile

County Lewis County WA
State Washington (WA)
Population 78
Area 2,436 sq miles
FEMA Region Moderate

// Other Washington Counties