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Natural hazard risk in Lewis County, Washington

Updated October 30, 2026. Based on FEMA, NOAA and OpenFEMA data. Published by Humblebee.

FEMA overall Risk Index rating: Relatively Moderate (score 89.6 of 100)[5]

Expected annual loss (FEMA)
$70.9 million[1]
Federal disaster declarations since 1964
35[2]
NFIP flood claims paid, 1978 to 2026
$82.7 million[3]
Tornadoes recorded, 1950 to 2024
3[4]

FEMA rates overall natural hazard risk in Lewis County Relatively Moderate compared with other US counties, with a Risk Index score of 89.6 out of 100[5]. Among its 18 hazards, FEMA's highest hazard scores in the county are earthquake, landslide and volcanic activity[6].

FEMA risk ratings for each hazard

Ratings and expected losses from the FEMA National Risk Index. Each rating compares this county with all US counties for that hazard, from Very Low to Very High. They are planning estimates, not predictions, and they do not describe any single property.

FEMA's National Risk Index estimates Expected Annual Loss from all 18 natural hazards in Lewis County at $70.9 million a year[1]. This is a FEMA estimate of average yearly loss, not money anyone paid[7]. FEMA's sorted loss values show the largest are inland flooding at $36.8 million a year, then earthquake at $30.4 million a year, then avalanche at $1.3 million a year[8]. FEMA rates social vulnerability Relatively Moderate, with a score of 58.2[9]. FEMA rates community resilience Relatively Moderate, with a score of 45.0[10].

Hazards sorted by FEMA hazard-type Risk Index score, highest first
HazardFEMA risk ratingExpected annual loss
EarthquakeRelatively Moderate$30.4 million[11]
LandslideRelatively Moderate$195,000[12]
Volcanic ActivityRelatively Moderate$287,000[13]
Inland FloodingRelatively Moderate$36.8 million[14]
AvalancheRelatively High$1.3 million[15]
Heat WaveRelatively Low$1.2 million[16]
WildfireRelatively Low$263,000[17]
Winter WeatherRelatively Low$40,000[18]
Ice StormRelatively Low$37,000[19]
LightningRelatively Low$103,000[20]
Strong WindRelatively Low$168,000[21]
TornadoVery Low$162,000[22]
DroughtVery Low$46[23]
HailVery Low$12,000[24]
Cold WaveVery Low$149[25]

Rated Not Applicable by FEMA for this county: coastal flooding, hurricane, tsunami[26].

Social vulnerability and community resilience

FEMA uses these two ratings to scale expected losses into the Risk Index.

FEMA measureRatingScore
Social vulnerabilityRelatively Moderate58.2[9]
Community resilienceRelatively Moderate45.0[10]

Flooding and flood insurance

FEMA rates inland flooding risk Relatively Moderate in Lewis County, with a score of 90.9 out of 100[14]. OpenFEMA lists 1,035 residential flood insurance contracts in force out of 35,507 residential structures, a penetration rate of 2.9%[27]. OpenFEMA NFIP claims data records 2,102 claims for losses in the county from 1978 to 2026, and NFIP paid $82.7 million in total[3]. For a specific address, use FEMA's Flood Map Service Center[28].

Measure Value
Inland Flooding, FEMA risk rating[14] Relatively Moderate, $36.8 million expected loss a year
NFIP residential flood policies in force (2026)[27] 1,035 of 35,507 homes
NFIP flood claims, 1978 to 2026[3] 2,102 filed, $82.7 million paid

Is a specific address in a flood zone? Only FEMA's flood maps answer that, property by property[28]. This page describes the whole county.

Search an address on the FEMA Flood Map Service Center

Disaster declarations and tornado records

OpenFEMA lists 35 federal disaster declarations for natural hazards that include Lewis County since 1964[2]. By incident type, flood accounts for 19 and severe storm for 13[2]. The most recent is DR-4906-WA, declared 2026-04-07[29]. NOAA's tornado database records 3 tornadoes touching the county from 1950 to 2024, and the most recent was on 2011-05-27[4].

Federal disaster declarations for natural hazards that include Lewis County, since 1964
Incident type Declarations
Flood[2] 19
Severe Storm[2] 13
Volcanic Eruption[2] 1
Coastal Storm[2] 1
Earthquake[2] 1
Most recent declarations
Declaration Incident Declared
DR-4906-WA[29] Severe Storms, Straight-Line Winds, Flooding, Landslides, And Mudslides 2026-04-07
EM-3629-WA[29] Severe Storms, Straight-Line Winds, Flooding, Landslides, And Mudslides 2025-12-12
DR-4775-WA[29] Severe Winter Storms, Straight-Line Winds, Flooding, Landslides, And Mudslides 2024-04-28
DR-4682-WA[29] Severe Winter Storm, Straight-Line Winds, Flooding, Landslides, And Mudslides 2023-01-12
DR-4650-WA[29] Severe Winter Storms, Snowstorms, Straight-Line Winds, Flooding 2022-03-29

How to prepare

Steps from Ready.gov, FEMA's preparedness site, for the hazards with the highest FEMA ratings here. Follow instructions from local officials and the National Weather Service when a warning is issued.

Earthquakes

Before

  • Practice Drop, Cover, and Hold On with your family and coworkers.
  • Sign up for earthquake alerts that can warn you before shaking starts.
  • Make a plan with an out-of-state contact and a place to meet if you get separated.
  • Anchor heavy items such as bookcases, refrigerators and water heaters, and keep heavy things on low shelves.
  • Consider earthquake insurance. Standard homeowners policies do not cover earthquake damage.

During

  • Drop to your hands and knees, cover your head and neck, and hold on until the shaking stops.
  • Indoors, stay where you are and avoid doorways. Outdoors, move to an open area away from buildings and power lines.
  • If you are driving, pull over, stop and set the parking brake.

Source: Ready.gov, earthquakes

Floods

Before

  • Check your flood risk with FEMA's Flood Map Service Center, and remember that floods do not follow map lines.
  • Sign up for your community's warning system. NOAA Weather Radio also broadcasts alerts.
  • Buy flood insurance through the NFIP well before a disaster. Homeowners policies do not cover flooding, and a new policy typically takes up to 30 days to go into effect.
  • Make a household plan with evacuation routes, shelter locations and what to do in a flash flood.
  • Keep important documents in a waterproof container and make password-protected digital copies.

During

  • If you are told to evacuate, leave right away and never drive around barricades.
  • Do not walk, swim or drive through floodwater. Six inches of moving water can knock you down.
  • If you are trapped in a building, go to the highest level, but do not climb into a closed attic.

Source: Ready.gov, floods

Questions people ask

Is Lewis County, WA at risk of flooding?
FEMA rates inland flooding risk Relatively Moderate in Lewis County compared with other US counties[14]. For a specific address, check FEMA's Flood Map Service Center[28].
Does Lewis County, WA get tornadoes?
NOAA's tornado database records 3 tornadoes in Lewis County from 1950 to 2024[4]. FEMA rates tornado risk Very Low compared with other US counties[22].
Is Lewis County, WA at risk of earthquakes?
FEMA rates earthquake risk Relatively Moderate in Lewis County, with an Expected Annual Loss of $30.4 million a year[11].
How many disasters have been declared in Lewis County, WA?
OpenFEMA lists 35 federal disaster declarations for natural hazards that include Lewis County since 1964[2].
How can I check the flood zone of a home in Lewis County, WA?
Look up the address in FEMA's Flood Map Service Center or ask the local floodplain manager[28].

Facts and sources

  1. FEMA National Risk Index (version 1.20, December 2025): Expected Annual Loss from all 18 natural hazards in Lewis County is $70.9 million a year (Expected Annual Loss rating Relatively Moderate, score 87.9). Of this, buildings account for $57.7 million, injuries and deaths (converted to dollars by FEMA) for $13.2... FEMA National Risk Index
  2. OpenFEMA Disaster Declarations Summaries list 35 federal disaster declarations for natural hazards that include Lewis County since 1964 (33 major disaster, 2 emergency or fire management). By incident type: flood 19, severe storm 13, volcanic eruption 1, coastal storm 1, earthquake 1. Biological (such as COVID-19)... OpenFEMA Disaster Declarations
  3. HazardFacts tally of OpenFEMA NFIP Redacted Claims (losses from 1978 to 2026): 2,102 National Flood Insurance Program claims were filed for losses in Lewis County, 1,877 of them with a payment, and NFIP paid $82.7 million in total (building, contents and increased cost of compliance, in dollars of the year paid).... OpenFEMA NFIP claims
  4. NOAA Storm Prediction Center tornado database (1950 to 2024): 3 recorded tornadoes touched Lewis County. The strongest were rated F2 (most recent of them on 1965-11-10). 0 were rated F3/EF3 or stronger. The most recent recorded tornado was on 2011-05-27. Ratings used the Fujita scale until early 2007 and the... NOAA Storm Prediction Center
  5. FEMA National Risk Index (version 1.20, December 2025): the overall natural hazard Risk Index rating for Lewis County is Relatively Moderate, with a Risk Index score of 89.6 out of 100. The score is the county's percentile rank among all US counties. FEMA National Risk Index
  6. Among the 18 hazards in the FEMA National Risk Index (version 1.20, December 2025), the hazards with the highest hazard-type Risk Index scores for Lewis County are earthquake (97.3, Relatively Moderate), landslide (96.5, Relatively Moderate), volcanic activity (95.1, Relatively Moderate). HazardFacts sorted FEMA's... FEMA National Risk Index
  7. FEMA's National Risk Index FAQ (December 2025): Expected Annual Loss is FEMA's estimate of the average economic loss in dollars from natural hazards each year. The index is not meant to predict how much damage a community will have in the next year, and a hazard can still cause damage where a rating is low. Scores... FEMA National Risk Index documentation
  8. HazardFacts sorted FEMA's hazard-type Expected Annual Loss values for Lewis County (National Risk Index v1.20): the largest are inland flooding ($36.8 million a year), earthquake ($30.4 million a year), avalanche ($1.3 million a year), out of $70.9 million a year from all 18 hazards. FEMA National Risk Index
  9. FEMA National Risk Index (version 1.20, December 2025): Social Vulnerability rating for Lewis County is Relatively Moderate (score 58.2). FEMA describes social vulnerability as how susceptible social groups are to the harm natural hazards cause. FEMA National Risk Index
  10. FEMA National Risk Index (version 1.20, December 2025): Community Resilience rating for Lewis County is Relatively Moderate (score 45.0). FEMA describes community resilience as a community's ability to prepare for, withstand and recover from hazards. FEMA National Risk Index
  11. FEMA National Risk Index (version 1.20, December 2025), earthquake in Lewis County: Risk Index rating Relatively Moderate (score 97.3 of 100). Expected Annual Loss $30.4 million a year (rating Relatively High). FEMA's modeled annual frequency is 0.0194 events per year. FEMA National Risk Index
  12. FEMA National Risk Index (version 1.20, December 2025), landslide in Lewis County: Risk Index rating Relatively Moderate (score 96.5 of 100). Expected Annual Loss $195,000 a year (rating Relatively Moderate). FEMA National Risk Index
  13. FEMA National Risk Index (version 1.20, December 2025), volcanic activity in Lewis County: Risk Index rating Relatively Moderate (score 95.1 of 100). Expected Annual Loss $287,000 a year (rating Relatively Moderate). FEMA National Risk Index
  14. FEMA National Risk Index (version 1.20, December 2025), inland flooding in Lewis County: Risk Index rating Relatively Moderate (score 90.9 of 100). Expected Annual Loss $36.8 million a year (rating Relatively Moderate). Annualized frequency 0.29 event-days per year, from recorded occurrences over a period of record... FEMA National Risk Index
  15. FEMA National Risk Index (version 1.20, December 2025), avalanche in Lewis County: Risk Index rating Relatively High (score 88.0 of 100). Expected Annual Loss $1.3 million a year (rating Relatively Moderate). Annualized frequency 0.7 events per year, from recorded occurrences over a period of record of 28 years. FEMA National Risk Index
  16. FEMA National Risk Index (version 1.20, December 2025), heat wave in Lewis County: Risk Index rating Relatively Low (score 77.9 of 100). Expected Annual Loss $1.2 million a year (rating Relatively Low). Annualized frequency 3.24 event-days per year, from recorded occurrences over a period of record of 18 years. FEMA National Risk Index
  17. FEMA National Risk Index (version 1.20, December 2025), wildfire in Lewis County: Risk Index rating Relatively Low (score 76.6 of 100). Expected Annual Loss $263,000 a year (rating Relatively Low). FEMA's modeled annual frequency is 0.0001 events per year. FEMA National Risk Index
  18. FEMA National Risk Index (version 1.20, December 2025), winter weather in Lewis County: Risk Index rating Relatively Low (score 40.1 of 100). Expected Annual Loss $40,000 a year (rating Relatively Low). Annualized frequency 29.26 events per year, from recorded occurrences over a period of record of 18 years. FEMA National Risk Index
  19. FEMA National Risk Index (version 1.20, December 2025), ice storm in Lewis County: Risk Index rating Relatively Low (score 35.5 of 100). Expected Annual Loss $37,000 a year (rating Relatively Low). Annualized frequency 0.51 event-days per year, from recorded occurrences over a period of record of 68 years. FEMA National Risk Index
  20. FEMA National Risk Index (version 1.20, December 2025), lightning in Lewis County: Risk Index rating Relatively Low (score 32.3 of 100). Expected Annual Loss $103,000 a year (rating Relatively Low). Annualized frequency 6.58 events per year, from recorded occurrences over a period of record of 24 years. FEMA National Risk Index
  21. FEMA National Risk Index (version 1.20, December 2025), strong wind in Lewis County: Risk Index rating Relatively Low (score 21.3 of 100). Expected Annual Loss $168,000 a year (rating Relatively Low). Annualized frequency 0.02 events per year, from recorded occurrences over a period of record of 38 years. FEMA National Risk Index
  22. FEMA National Risk Index (version 1.20, December 2025), tornado in Lewis County: Risk Index rating Very Low (score 17.4 of 100). Expected Annual Loss $162,000 a year (rating Very Low). Annualized frequency 0.14 events per year, from recorded occurrences over a period of record of 38 years. FEMA National Risk Index
  23. FEMA National Risk Index (version 1.20, December 2025), drought in Lewis County: Risk Index rating Very Low (score 13.1 of 100). Expected Annual Loss $46 a year (rating Very Low). Annualized frequency 2.62 event-days per year, from recorded occurrences over a period of record of 22 years. FEMA National Risk Index
  24. FEMA National Risk Index (version 1.20, December 2025), hail in Lewis County: Risk Index rating Very Low (score 5.4 of 100). Expected Annual Loss $12,000 a year (rating Very Low). Annualized frequency 0.03 events per year, from recorded occurrences over a period of record of 37 years. FEMA National Risk Index
  25. FEMA National Risk Index (version 1.20, December 2025), cold wave in Lewis County: Risk Index rating Very Low (score 3.0 of 100). Expected Annual Loss $149 a year (rating Very Low). Annualized frequency 0 event-days per year, from recorded occurrences over a period of record of 18 years. FEMA National Risk Index
  26. FEMA National Risk Index (version 1.20, December 2025) rates these hazards Not Applicable for Lewis County: coastal flooding, hurricane, tsunami. FEMA uses Not Applicable when its source data has no historical record of the hazard in the community and the hazard is not considered geographically possible there. FEMA National Risk Index documentation
  27. NFIP Residential Penetration Rates (OpenFEMA, as of 2026-08-03): 1,035 residential flood insurance contracts were in force in Lewis County, out of 35,507 residential structures, a penetration rate of 2.9%. OpenFEMA NFIP penetration rates
  28. FEMA's Flood Map Service Center is the official public source for flood maps (Flood Insurance Rate Maps) produced under the National Flood Insurance Program. Flood zones apply to specific properties: look up an address there or ask the local floodplain manager. County-level ratings do not tell you the flood zone of... FEMA Flood Map Service Center
  29. Most recent federal disaster declarations for natural hazards (table on this page). OpenFEMA Disaster Declarations

FEMA's National Risk Index compares each county with all other US counties. Ratings are relative (Very Low to Very High), not a measure of safety. Never call a place safe, unsafe, good or bad to live in. Risk Index and Expected Annual Loss values are FEMA estimates for planning. They do not predict next year's losses and do not apply to a single property. Flood zones are set by FEMA flood maps for specific properties. County ratings and flood insurance counts do not tell anyone whether an address is in a flood zone. Disaster declaration, NFIP and tornado counts are records of the past for this county only. Do not compare with other counties unless a fact does.

Federal Emergency Management Agency (FEMA), National Risk Index Dataset: National Risk Index Counties, v1.20 (December 2025). Retrieved from fema.maps.arcgis.com on October 30, 2026. This product uses the Federal Emergency Management Agency's National Risk Index dataset API or downloadable datasets but is not endorsed by FEMA. The Federal Government or FEMA cannot vouch for the data or analyses derived from these data after the data have been retrieved from the Agency's website(s). This product uses the FEMA OpenFEMA API, but is not endorsed by FEMA.