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Snohomish County, Washington Flood Zones

Check an Address in Snohomish County

Enter any address in Snohomish County, Washington to see its FEMA flood zone

The Flooding Character of Snohomish County

Atmospheric river events and coastal flooding are significant flood hazards in Snohomish County. Recent events include coastal flooding during high tides in December 2022, exacerbated by strong winds and King Tides. Inland flooding from atmospheric rivers has also occurred, such as in December 2023 and January and November 2021, bringing heavy rainfall and widespread inundation.

National Flood Insurance Program (NFIP) data indicates that properties in Zone A have experienced the highest number of claims, with an average payout of $17,211 and an average water depth of 5.4 feet. Properties in Zone X also show substantial claims, with higher average payouts ($31,953) but slightly lower average water depths (4.9 feet). Homeowners in coastal areas, those situated near rivers, and properties located in zones without a Base Flood Elevation (BFE) should pay particular attention to flood risk.

Summary generated from NOAA storm narratives and NFIP claim data for this county. Not predictive.

Read First-Hand Flood Stories from Snohomish County

5 NOAA storm reports from this county describe what happened, in the words of the meteorologists who were there.

Read Washington flood stories →

Flood Risk Data for Snohomish County

Snohomish County, Washington has recorded 14 flood-related events since 1996 according to NOAA's Storm Events Database, including 1 flash floods and 10 river or area floods. The county has received 36 federal disaster declarations, 13 of which involved flooding or coastal storms. Enter any address above to check its FEMA flood zone designation.

Snohomish County Disaster History

FEMA Disaster Declarations (1964–2025)

Disaster Declarations
36
Flood/Coastal Disasters
13
Latest Disaster
Severe Storms, Straight-line Winds, Flooding, Landslides, And Mudslides (2025-12-09)

Source: OpenFEMA Disaster Declarations Summaries.

Recent Disaster Declarations in Snohomish County

DeclarationTypeDate
Severe Storms, Straight-line Winds, Flooding, Landslides, And MudslidesFloodDec 9, 2025
Severe Winter Storm, Straight-line Winds, Flooding, Landslides, And MudslidesSevere StormNov 3, 2022
Bolt Creek FireFireSep 10, 2022
Severe Winter Storm, Straight-line Winds, Flooding, Landslides, And MudslidesSevere StormDec 29, 2020
Covid-19BiologicalJan 20, 2020
Covid-19 PandemicBiologicalJan 20, 2020
Severe Storms, Flooding, Landslides, And MudslidesFloodJan 20, 2020
Severe Winter Storms, Straight-line Winds, Flooding, Landslides, Mudslides, TornadoSevere StormDec 10, 2018
Severe Storms, Straight-line Winds, Flooding, Landslides, And MudslidesSevere StormNov 12, 2015
Severe WindstormSevere StormAug 29, 2015

Recorded Flood Events in Snohomish County

NOAA Storm Events Database (1996–2025)

Total Flood Events
14
River/Area Floods
10
Flash Floods
1
Coastal/Storm Surge
3
Total Property Damage
$14.3M

Source: NOAA National Weather Service Storm Events Database.

Recent Flood Events in Snohomish County

TypeDateDamage
FloodDec 5, 20230.00K
Coastal FloodDec 27, 2022
FloodNov 12, 20212.42M
FloodJan 12, 2021329.00K
Flash FloodApr 20, 20170.00K
FloodNov 17, 2015250.00K
Storm Surge/TideJan 26, 2012
Coastal FloodDec 17, 2012200.00K
FloodJan 16, 201150.00K
FloodDec 12, 20101.10M

Snohomish County Flood History

Flood — Dec 5, 2023

An atmospheric river event brought flooding, record breaking rainfall, and record high temperatures to Western Washington.

Coastal Flood — Dec 27, 2022

Coastal flooding between 8 AM - 11 AM high tide cycle on 12/27. The event was a result of King Tides, coinciding with significantly strong low pressure in the area and strong winds. Wind gusts of up to 64 MPH occurred in the event as well as observed tidal conditions 1-2 feet above the HAT.

Flood — Nov 12, 2021

An upper level trough Gulf Low continued off the west coast that brought a series of atmospheric rivers resulting in flooding across parts of western Washington. This second atmospheric river episode of the month was a set of three atmospheric rivers back-to-back-to-back. Water vapor transport into Western Washington averaged 160 - 200% of normal during the period of 11 November - 16 November. ...

Flood — Jan 12, 2021

The period from January 10 to 16 continued a pattern of a strong and persistent Aleutian Low pressure system in the eastern Pacific that began December 29, 2020 and which directed the jet stream and primary storm track at Washington State. This resulted in a series of atmospheric rivers and wind storms that battered Washington State. Water vapor transport into Washington State averaged 160-200...

Flash Flood — Apr 20, 2017

A convergence zone caused heavy rain and flash flooding in Snohomish county, near Marysville and Lake Stevens.

Source: NOAA National Weather Service Storm Events Database.

Snohomish County NFIP Flood Insurance Claims

Total Claims Filed
1,600
Total Paid Out
$28.9M
Avg Claim
$22,310
Avg Water Depth
9.4 ft

Claims by Flood Zone

A Zones (High Risk)
1,249
X Shaded (500-yr)
24
X Unshaded (Low)
52

Source: OpenFEMA NFIP Individual Claims (2.25M records analyzed).

Flood Zone Types in Snohomish County

FEMA assigns flood zone designations to areas in Snohomish County, Washington:

AE High Risk — 1% annual chance of flooding. Insurance required.

VE Very High Risk — Coastal flooding with wave action.

X (Shaded) Moderate Risk — 500-year floodplain.

X Low Risk — Outside major floodplains.

View all flood zone types →

Flood Insurance in Snohomish County

Properties in Snohomish County, Washington that are in FEMA-designated Special Flood Hazard Areas (zones A and V) with federally backed mortgages are required to carry flood insurance.

Even outside high-risk zones, flood insurance is recommended. From 2014 to 2024, nearly one-third of NFIP claims came from outside the high-risk Special Flood Hazard Area.

Visit FloodSmart.gov to find an agent and get a quote.