Snohomish County, Washington severe weather history spans 53 recorded events between 1970 and 2023. The dominant hazard is flood, accounting for 18.9% of all recorded events. It ranks #3,033 nationally and #16 in Washington.
53
Recorded events
44
Direct deaths
13
Direct injuries
$84.2M
Property damage
The record
What the Snohomish County, Washington severe weather history record shows
Across the archive, Snohomish County, Washington severe weather history averages 1.0 recorded events a year. The busiest stretch on record is the 2000s, with 21 events logged in that decade alone. Roughly 5 events fall before 1990 and 48 from 1990 onward — a gap that reflects the expansion of NOAA reporting practice as much as the weather itself.
The deadliest hazard in the Snohomish County, Washington record is debris flow, responsible for 43 direct deaths. The costliest is debris flow, with $60.0M in reported property damage. In total, 9 distinct hazard types appear in this county archive, each listed with its own dated record below.
By hazard type
Every hazard type recorded in Snohomish County
| Hazard | Events | Deaths | Damage | Max | Span |
|---|---|---|---|---|---|
| Flood | 10 | 0 | $14.1M | 0 | 1997–2023 |
| Lightning | 9 | 1 | $69K | 0 | 1996–2008 |
| Funnel Cloud | 9 | 0 | $0 | 0 | 1997–2016 |
| Tornado | 7 | 0 | $56K | F2 | 1970–2006 |
| Thunderstorm Wind | 5 | 0 | $35K | 50 | 1976–2012 |
| Debris Flow | 5 | 43 | $60.0M | 0 | 1997–2017 |
| Heavy Rain | 4 | 0 | $10.0M | 0 | 2001–2007 |
| Hail | 3 | 0 | $0 | 1 | 2001–2006 |
| Flash Flood | 1 | 0 | $0 | 0 | 2017–2017 |
Decade by decade
Snohomish County, Washington severe weather history by decade
Reporting practice changed over time — early decades are undercounted, not calmer.
Tornado tracks
Paths crossing this county
7 mapped tornado paths intersect this county: 7 touched down inside it and 0 crossed in from a neighbouring county. This comes from path geometry, not county-tagged reports.
| Date | Scale | Deaths | Injuries | Path length | Origin |
|---|---|---|---|---|---|
| 1986-05-13 | EF2 | 0 | 0 | 0.3 mi | Touched down here |
| 1970-11-24 | EF2 | 0 | 0 | 0.3 mi | Touched down here |
| 2005-05-18 | EF1 | 0 | 0 | 0.2 mi | Touched down here |
| 1971-10-26 | EF1 | 0 | 0 | 3.0 mi | Touched down here |
| 2006-06-16 | EF0 | 0 | 0 | 0.5 mi | Touched down here |
| 2004-06-05 | EF0 | 0 | 0 | 0.1 mi | Touched down here |
| 1997-08-24 | EF0 | 0 | 0 | 0.5 mi | Touched down here |
Significant events
Deadliest events on record in Snohomish County
| Date | Type | Location | Deaths | Injuries | Damage |
|---|---|---|---|---|---|
| Mar 22, 2014 | Debris Flow | OSO | 43 | 12 | $60.0M |
| Sep 15, 1996 | Lightning | MARYSVILLE | 1 | 0 | $0 |
| Aug 6, 1997 | Lightning | ARLINGTON | 0 | 1 | $0 |
From the record
What the reports say
Written by National Weather Service staff at the time of the event · public domain
Over a dozen roads were closed due to high water and 20 families were evacuated from their apartments. Roads near Mill Creek and Edmonds will be closed for nearly a month to repair large sinkholes near and under the streets. About 300 residents had minor water damage to their homes.
More than 50 roads in the county were flooded and about 40 were closed, including Highway 9. Highway 530 was closed in multiple locations. Schools in the Stanwood-Camano district were closed for 2 days. Most of Stanwood flooded, even businesses that hadn't flooded in 25 years. Many people were able to evacuate animals before the waters rose, however dozens had to leave via boat. Nearly 500 homes were flooded. Flood waters blew a hole in a dike on Ebey Island.
Record flooding occurred on the Cowlitz, Nooksack, Puyallup, Nisqually, |Skykomish, Stillaguamish, Carbon, Snoqualmie, and Bogachiel. Major flooding occurred on the Tolt, Snohomish, Skokomish, Skagit, and White rivers. Other rivers flooding were the Satsop, Cedar, Wynoochee, Elwha, Deschutes, Dungeness, Skookumchuck, and Chehalis.
Context
Risk, population and federal disasters
Relatively High
FEMA NRI risk rating
844,430
Population (ACS)
$696K
Median home value
37
Federal declarations
| Declared | Incident | Title | Type |
|---|---|---|---|
| Apr 7, 2026 | Flood | SEVERE STORMS, STRAIGHT-LINE WINDS, FLOODING, LANDSLIDES, AND MUDSLIDES | DR |
| Dec 12, 2025 | Flood | SEVERE STORMS, STRAIGHT-LINE WINDS, FLOODING, LANDSLIDES, AND MUDSLIDES | EM |
| Jan 12, 2023 | Severe Storm | SEVERE WINTER STORM, STRAIGHT-LINE WINDS, FLOODING, LANDSLIDES, AND MUDSLIDES | DR |
| Sep 10, 2022 | Fire | BOLT CREEK FIRE | FM |
| Apr 8, 2021 | Severe Storm | SEVERE WINTER STORM, STRAIGHT-LINE WINDS, FLOODING, LANDSLIDES, AND MUDSLIDES | DR |
| Apr 23, 2020 | Flood | SEVERE STORMS, FLOODING, LANDSLIDES, AND MUDSLIDES | DR |
Quick answers
Frequently asked
How many severe weather events have been recorded in Snohomish County, Washington?
53 events are on record between 1970 and 2023, causing 44 direct deaths and $84.2M in property damage.
What is the most common severe weather hazard in Snohomish County?
Flood, with 10 recorded events — 18.9% of everything in the archive for this county.
How many tornadoes have crossed Snohomish County?
7 mapped tornado paths intersect the county boundary; 7 of them touched down inside it. This is derived from path geometry, not county-tagged reports.
How many federal disaster declarations cover Snohomish County?
37 federal disaster declarations from FEMA include Snohomish County, each tied to a specific incident period.
How risky is Snohomish County compared with the rest of the country?
FEMA's National Risk Index rates Snohomish County as relatively high risk, placing it in the 98 percentile of its state for expected annual loss.
Where does the Snohomish County, Washington severe weather history data come from?
Every figure is drawn from United States federal public-domain records: NOAA/NCEI Storm Events for the event archive, NOAA SPC SVRGIS for mapped tornado paths, FEMA for disaster declarations and risk ratings, and the U.S. Census for population context. Dates are shown in UTC and recent entries may still be revised by NOAA.
Nearby
Neighbouring counties
- Skamania County 11
- Spokane County 249
- Skagit County 16
- Stevens County 117
- San Juan County 4
- Thurston County 28
Cite this page
“Snohomish County, Washington.” Severe Weather History. severeweatherhistory.com/county/washington/snohomish-county/ · Data: NOAA/NCEI, FEMA, U.S. Census — public domain.