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Snohomish County, Washington

Natural disaster risk, federal disaster history and flood insurance facts.

Relatively High overall risk
3rd of 39highest risk in Washington
$409Mexpected losses a year
35federal declarations
1 in 143homes with flood insurance
Photo: craigdietrich, CC BY 2.0

Snohomish County, Washington has a relatively high overall risk from natural hazards in FEMA's National Risk Index. Its risk score is higher than 98% of US counties. It ranks 3rd of 39 counties in Washington. The costliest hazards here are earthquakes, inland flooding and landslides. FEMA estimates about $409 million a year in expected losses, or roughly $494 per resident. Since 1964 it has been included in 35 federal disaster or emergency declarations for natural events (31 major disasters). The most recent was in April 2026 (severe storms, straight-line winds, flooding, landslides and mudslides). Fewer than 1 in 100 homes here carry federal flood insurance (1,769 policies). Since 1978, federal flood insurance has paid about $37 million on 1,961 claims here.

FEMA National Risk Index December 2025; OpenFEMA declarations to Nov 6, 2026; NFIP records. Updated November 6, 2026.

Top risks in Snohomish County

$247 million a yearExpected losses. Damaging events about once every 30 years.
  • Ask whether an older house is bolted to its foundation.
  • Consider separate earthquake insurance where risk is high.
$112 million a yearExpected losses. Damaging events about once every 3 years.
  • Check the FEMA flood map for your address, and ask the seller or landlord about past flooding.
  • Price a flood policy now. Most new federal policies take 30 days to start.

Landslide

Very High
$24.7 million a yearExpected losses. Damaging events about 4 times a year.
  • Look for cracks, tilting trees or fences on slopes nearby.
  • Ask the county about past slides on the street.
HazardRatingScoreExpected loss a year
EarthquakeHigh99.3
$247M
Inland floodingHigh95.7
$112M
LandslideVery High100.0
$25M
Heat waveHigh96.9
$12M
Ice stormVery High98.0
$4M
Coastal floodingModerate77.6
$2M
Cold waveLow64.4
$2M
AvalancheHigh87.4
$2M
LightningHigh86.1
$1M
TornadoLow38.8
$1M
Winter weatherHigh94.0
$761K
Volcanic activityModerate96.4
$675K
WildfireVery Low61.5
$120K
Strong windVery Low7.8
$74K
HailVery Low15.1
$66K
TsunamiVery Low7.7
$51K
DroughtVery Low13.0
$44

Scores are percentiles: a score of 90 means higher risk than about 90% of US counties for that hazard. Hazards FEMA does not rate here are left out. Social vulnerability is very low and community resilience is relatively high in FEMA's measures.

Federal disaster history

Recent disasters nationwide ›

Declarations by decade

Federal declarations for natural events that included Snohomish County. 2020s bar runs to November 2026.

By type

Severe Storm15
Flood13
Earthquake2
Mud/Landslide2
Volcanic Eruption1
Coastal Storm1

Most recent

Apr 7, 2026Severe Storms, Straight-Line Winds, Flooding, Landslides, and MudslidesMajor disaster
Dec 12, 2025Severe Storms, Straight-Line Winds, Flooding, Landslides, and MudslidesEmergency
Jan 12, 2023Severe Winter Storm, Straight-Line Winds, Flooding, Landslides, and MudslidesMajor disaster
Sep 10, 2022Bolt Creek FireFire management
Apr 8, 2021Severe Winter Storm, Straight-Line Winds, Flooding, Landslides, and MudslidesMajor disaster
Apr 23, 2020Severe Storms, Flooding, Landslides, and MudslidesMajor disaster
Mar 4, 2019Severe Winter Storms, Straight-Line Winds, Flooding, Landslides, Mudslides, TornadoMajor disaster
Jan 15, 2016Severe Storms, Straight-Line Winds, Flooding, Landslides, and MudslidesMajor disaster
Oct 15, 2015Severe WindstormMajor disaster
Apr 2, 2014Flooding and MudslidesMajor disaster
Show all 35
Mar 24, 2014Flooding and MudslidesEmergency
Mar 5, 2012Severe Winter Storm, Flooding, Landslides, and MudslidesMajor disaster
Mar 2, 2009Severe Winter Storm and Record and Near Record SnowMajor disaster
Jan 30, 2009Severe Winter Storm, Landslides, Mudslides, and FloodingMajor disaster
Dec 8, 2007Severe Storms, Flooding, Landslides, and MudslidesMajor disaster
Feb 14, 2007Severe Winter Storm, Landslides, and MudslidesMajor disaster
Dec 12, 2006Severe Storms, Flooding, Landslides, and MudslidesMajor disaster
May 17, 2006Severe Storms, Flooding, Tidal Surge, Landslides, and MudslidesMajor disaster
Sep 7, 2005Hurricane Katrina EvacuationEmergency
Nov 7, 2003Severe Storms and FloodingMajor disaster
Mar 1, 2001EarthquakeMajor disaster
Apr 2, 1997Heavy Rains, Snow Melt, Flooding, Land & Mud SlidesMajor disaster
Jan 17, 1997Severe Winter Storms, Land & Muds Slides,FloodingMajor disaster
Feb 9, 1996High Winds, Severe Storms and FloodingMajor disaster
Jan 3, 1996Severe Storms, High Wind, and FloodingMajor disaster
Mar 4, 1993Severe Storms & High WindMajor disaster
Mar 8, 1991Severe Storms & High TidesMajor disaster
Nov 26, 1990Severe Storms & FloodingMajor disaster
Dec 15, 1986Severe Storms & FloodingMajor disaster
May 21, 1980Volcanic Eruption, Mt. St. HelensMajor disaster
Dec 31, 1979Storms, High Tides, Mudslides & FloodingMajor disaster
Dec 10, 1977Severe Storms,Mudslides, & FloodingMajor disaster
Dec 13, 1975Severe Storms & FloodingMajor disaster
May 11, 1965EarthquakeMajor disaster
Dec 29, 1964Heavy Rains & FloodingMajor disaster

Washington also had 51 statewide declarations that did not name single counties.

Storm history since 1970

Tornado risk by county ›

The National Weather Service has logged 45 storm reports in Snohomish County since 1970, with 44 deaths and 13 injuries and about $84.3 million in reported damage. The strongest on record here was an F2 tornado on November 24, 1970.

7tornadoes
3hail reports, largest 1 inches
5damaging thunderstorm winds
11floods and flash floods

Strongest tornadoes

DateStrengthNearHurt / killed
Nov 24, 1970F2–0 / 0
May 13, 1986F2–0 / 0
Oct 26, 1971F1–0 / 0
May 18, 2005F1Arlington0 / 0
Aug 24, 1997F0Snohomish0 / 0

Most damaging storms

DateTypeNearDamage
Mar 22, 2014Debris FlowOso$60M
Dec 3, 2007Heavy RainLynnwood$10M
Jan 7, 2009FloodGold Bar$7M
Nov 4, 2006FloodSnohomish$3M
Nov 12, 2021FloodCedarhome$2M
Dec 12, 2010FloodGranite Falls$1M

Source: NOAA Storm Events Database, county-based reports through Dec 5, 2023. Tornado records start in 1950, hail and wind in 1955, and floods and other storm types in 1996, so older decades undercount. Damage is in dollars of the year it happened and is often an estimate. Winter storms, heat and hurricanes are logged by forecast zone, not county, so they are not counted here.

Flood insurance in Snohomish County

Check your address flood zone ›
0.7%of homes have federal flood insurance (1,769 policies)
27.3%of homes in mapped high-risk flood zones are insured
$37.1 millionpaid on 1,961 flood claims since 1978
2006costliest year, with $7.9 million paid

National Flood Insurance Program (NFIP) records only; private flood policies are not included. Home counts as of Aug 3, 2026. Since 2021 NFIP prices each home separately under Risk Rating 2.0, so your price depends on the building, not the county. Ask an agent for a quote.

Homes in Snohomish County

$696,000median home value (Washington $564,600, US $332,700)
1990median year homes were built (Washington 1985, US 1980)
35%of homes built before 1980, before many modern wind, quake and flood building rules
4.6%of homes are mobile homes, which are the least safe in tornadoes and high winds

Older homes and mobile homes usually suffer more damage in storms, floods and earthquakes, and can cost more to insure. If you are buying, ask about roof age, foundation bolting and any retrofits. Source: US Census Bureau, American Community Survey 2020 to 2024 5-year estimates; 331,530 housing units.

Compare in Washington

All 39 ›
Largest countiesOverall riskTop hazard
King CountyVery HighEarthquake
Pierce CountyHighEarthquake
Snohomish CountyHighEarthquake
Spokane CountyModerateInland flooding
Clark CountyModerateInland flooding
Thurston CountyHighEarthquake
Kitsap CountyModerateEarthquake
Yakima CountyModerateInland flooding

Neighboring counties

CountyOverall riskDeclarations
King CountyVery High33
Kitsap CountyModerate14
Skagit CountyModerate27
Island CountyLow20
Chelan CountyModerate51

Common questions about Snohomish County

What is the biggest natural hazard in Snohomish County?

Earthquake has the highest expected yearly losses in Snohomish County, about $247 million a year in FEMA's estimate. Inland flooding is second at $112 million.

How many federal disasters has Snohomish County had?

Snohomish County has been included in 35 federal disaster or emergency declarations for natural events since 1964, including 31 major disasters. The most recent was Severe Storms, Straight-Line Winds, Flooding, Landslides, and Mudslides in April 2026.

Is Snohomish County a high-risk place to live?

Its overall rating is Relatively High, 3rd highest of 39 in Washington. A county rating covers the whole area. Risk at one address can be much higher or lower, so check the FEMA flood map and ask about the home's history.

Do I need flood insurance in Snohomish County?

Standard home insurance does not cover flooding. About 1 in 143 homes in Snohomish County has federal flood insurance. Lenders require it in mapped high-risk zones, but many flood claims come from outside those zones.

How many tornadoes has Snohomish County had?

NOAA records list 7 tornadoes in Snohomish County since 1950. The strongest was an F2 tornado on November 24, 1970. The weather service has also logged 3 hail reports and 11 floods here.

Sources: FEMA National Risk Index (December 2025), OpenFEMA Disaster Declarations Summaries, and NFIP policy and claims data. Hazard Compass is independent and not affiliated with FEMA. These figures describe the whole county, not a single property, and are not insurance or safety advice. Report a problem.