Washington landslides and avalanches
Every recorded landslide or avalanche record since 1996 · 35 counties with a record
NOAA's Storm Events Database records 254 landslide and avalanche records in Washington from 1996 through June 30, 2026, about 9.4 a year since 2000. The deadliest was the March 22, 2014 debris flow in Snohomish County: 43 deaths, 12 injuries and $74.8 million in damage in 2025 dollars. Washington ranks 4th of 37 states and territories by count and 5th of 37 per square mile.
Landslides and avalanches in Washington, 1996 to 2026
Landslide records per year (NOAA Storm Events); 2026 to June 30, 2026.
- recorded, no damage figure
- under $1 million
- $1 million or more
- $10 million or more
- $100 million or more, or 10 deaths
- $1 billion or more, or 100 deaths
- a year's colour: its recorded damage or deaths
- a year with a death
- Records
- 2541996 to June 30, 2026
- A year since 2000
- 9.4average
- Deaths
- 10256 injuries
- Damage, 2025 dollars
- $144Mas filed
- Busiest year
- 201426 records
Source: NOAA NCEI Storm Events Database, records through June 30, 2026; deaths and damage as filed, damage in 2025 dollars. Search the record at NCEI.
Are landslide and avalanche records common in Washington?
Washington averages about 9.4 landslide and avalanche records a year since 2000, 4th of 37 states and territories by count. The busiest year on record was 2014 (26). Per 10,000 square miles of land, Washington records 38 landslide and avalanche records since 1996, 5th of 37 states and territories by that measure.
Source: NOAA NCEI Storm Events Database, records since 1996, per 10,000 square miles of land area (Census Bureau 2024 Gazetteer; places under 1,000 square miles not ranked). Damage colours: Storm Events damage, 2025 dollars.
Which counties in Washington have the most landslide and avalanche records?
Per square mile, Kitsap County leads Washington: 10 days with a landslide or avalanche record since 1996, 25.3 per 1,000 square miles of land. By raw count, Okanogan County has the most landslide records (59 since 1996); large counties collect more records simply by covering more ground, so the ranking counts days with a record per unit of area (a storm filed for several forecast zones adds several records but one day).
Source: NOAA NCEI Storm Events Database, days with a record in the county since 1996 per 1,000 square miles of land (Census Bureau 2024 Gazetteer); in brackets, the count of records.
When is the slide season in Washington?
Washington's landslide and avalanche records by month. The busiest month is January (60 records).
The values, month by month
Jan 60 · Feb 29 · Mar 37 · Apr 18 · May 22 · Jun 9 · Jul 18 · Aug 19 · Sep 5 · Oct 8 · Nov 10 · Dec 19 (records).
Source: NOAA NCEI Storm Events Database, records by the month they began, since 1996.
What were the deadliest landslide and avalanche records in Washington?
| Date | Record | Character | Killed | Injured | Damage |
|---|---|---|---|---|---|
| 2014-03-22 | Debris FlowOso, Snohomish County On a warm and dry 22nd of March, 2014, a large landslide occurred four miles east of the town of Oso, Washington. The slide debris, traveling at over 60 miles per hour, crossed the entire river valley, covering an area of over a square mile with an approximate deposit thickness of 15 to 75 feet in some areas. The ... | 43 | 12 | $75M | |
| 2007-12-01 | AvalancheKing County and 2 more · forecast zone West Slopes Central Cascades And Passes One storm episode: 2 records, 2007-12-01 to 2007-12-02; the totals are the episode's. Two hikers were killed, and one injured, by an avalanche near Snoqualmie Pass. 3 snowboarders are presumed dead near Crystal Mountain. The snowfall that led to the avalanches was part of a deep Pacific storm system offshore the also created lowland snow in western Washington, strong winds particularly in the coastal ... | 5 | 1 | – | |
| 2012-02-19 | AvalancheKing County and 2 more · forecast zone West Slopes Central Cascades And Passes One storm episode: 3 records; the totals are the episode's. A strong front and moist westerly flow in its wake produced heavy snow in the Cascades. 3 different avalanches killed 4 and injured one. | 4 | 1 | – | |
| 1997-01-19 | Debris FlowJefferson County and 2 more · forecast zone Hood Canal/Kitsap Peninsula A mudslide kills a family of four while they were sleeping in their home. The house, on Bainbridge Island, slid down a hill into Puget Sound. 20 other homes in the vicinity were evacuated. Two days before the slide, the nearby city of Hoodsport received 2.91 inches of rain in 24 hours. | 4 | 0 | – | |
| 2023-02-19 | AvalancheChelan County · forecast zone Western Chelan County A group of 6 hikers caused a slab avalanche near Northeast Couloir route on Colchuck Peak. It resulted in 3 deaths and 1 injury. | 3 | 1 | – | |
| 1997-01-11 | AvalancheKing County and 2 more · forecast zone Central Cascade Foothills An avalanche killed 3 hikers. The hikers left on Dec. 27th, didn't return on the 29th as expected and weren't found until Jan 11th. They were found buried in an avalanche near Index. | 3 | 0 | – | |
| 2013-04-13 | AvalancheKing County and 2 more · forecast zone West Slopes Central Cascades And Passes One storm episode: 2 records; the totals are the episode's. Two separate avalanches killed two people and injured 7 near Snoqualmie Pass. | 2 | 7 | – | |
| 2026-01-09 | AvalancheKittitas County and Yakima County · forecast zone Upper Slopes Of The Est Washington Cascade Crest The Northwest Avalanche Center reported an avalanche occurred in Longs Pass when 4 backcountry skiers attempted to descend a south facing slope. Two of four skiers passed away from either injuries sustained from the avalanche or from being buried by avalanche debris. In their report, the Avalanche center suggested ... | 2 | 1 | – | |
| 1996-12-25 | AvalancheKing County and 2 more · forecast zone Central Slopes Northern Cascades And Passes Two hikers were killed by an avalanche in Alpental Valley northwest of Snoqualmie Pass. It was unsure when and how the avalanche started. | 2 | 0 | – | |
| 1999-02-14 | AvalancheSkagit County and 2 more · forecast zone West Slopes Northern Cascades And Passes A 19 year old snowboarder died in an avalanche on Mt Baker, while a 25 year old is assumed dead. The body was still buried in deep snow. | 2 | 0 | – |
Source: NOAA NCEI Storm Events Database: deaths direct and indirect, as filed by the National Weather Service, summed over each storm (one episode, or one named storm filed by several offices). Storm names from the titles of FEMA declarations that name the storm's counties.
The costliest landslide and avalanche records in Washington
| Date | Record | Character | Killed | Injured | Damage |
|---|---|---|---|---|---|
| 2014-03-22 | Debris FlowOso, Snohomish County | 43 | 12 | $75M | |
| 2009-10-10 | Debris FlowKittitas County and Yakima County · forecast zone East Slopes Of The Central Cascades | 0 | 0 | $34M | |
| 2009-01-07 | Debris FlowKing County and 2 more · forecast zone West Slopes Central Cascades And Passes One storm episode: 5 records in 4 places; the totals are the episode's. | 0 | 0 | $19M | |
| 2007-12-03 | Debris FlowJefferson County and 2 more · forecast zone Hood Canal Area One storm episode: 3 records in 3 places; the totals are the episode's. | 1 | 0 | $2.1M | |
| 2008-11-12 | Debris FlowKing County and 2 more · forecast zone East Puget Sound Lowlands | 0 | 0 | $1.8M | |
| 2008-02-07 | AvalancheChelan County and Okanogan County · forecast zone East Slopes Northern Cascades | 0 | 0 | $1.5M | |
| 2008-05-18 | Debris FlowChelan County and Okanogan County · forecast zone East Slopes Northern Cascades | 0 | 0 | $1.4M | |
| 2009-01-07 | AvalancheKittitas County and Yakima County · forecast zone East Slopes Of The Central Cascades | 0 | 0 | $1.4M |
Source: NOAA NCEI Storm Events Database: property and crop damage as estimated by the National Weather Service, in 2025 dollars.
Are landslide and avalanche records becoming more frequent in Washington?
Washington's count per decade against the whole country's, and its share. NOAA recorded every event type only from 1996, so earlier decades are not comparable; the share of the national total is the fairer comparison across decades.
| Decade | Washington | United States | Washington's share |
|---|---|---|---|
| 1996-99 | 18 | 98 | 18.4% |
| 2000s | 46 | 790 | 5.8% |
| 2010s | 157 | 1,304 | 12.0% |
| 2020-26 | 33 | 1,224 | 2.7% |
Source: NOAA NCEI Storm Events Database.
The most recent landslide and avalanche records in Washington
| Date | Record | Character | Killed | Injured | Damage |
|---|---|---|---|---|---|
| 2026-01-09 | AvalancheKittitas County and Yakima County · forecast zone Upper Slopes Of The Est Washington Cascade Crest | 2 | 1 | – | |
| 2025-11-18 | AvalancheKlickitat County · forecast zone Eastern Columbia River Gorge | 0 | 0 | – | |
| 2025-02-28 | AvalancheOkanogan County · forecast zone Western Okanogan County | 1 | 0 | $9K | |
| 2024-03-30 | AvalancheSkamania County and 2 more · forecast zone South Washington Cascades | 1 | 0 | – | |
| 2023-05-14 | Debris FlowSpirit Lake, Skamania County | 0 | 0 | $484K | |
| 2023-02-19 | AvalancheChelan County · forecast zone Western Chelan County | 3 | 1 | – | |
| 2022-11-04 | AvalancheSnohomish County · forecast zone Everett And Vicinity | 0 | 1 | – | |
| 2021-12-11 | AvalancheLewis County and Pierce County · forecast zone Cascades Of Pierce And Lewis Counties | 1 | 0 | – | |
| 2020-01-23 | AvalancheChelan County and Okanogan County · forecast zone East Slopes Northern Cascades | 1 | 0 | – | |
| 2017-04-02 | Debris FlowMiles, Lincoln County | 0 | 0 | $963K | |
| 2016-01-24 | AvalancheSkagit County and Whatcom County · forecast zone Cascades Of Whatcom And Skagit Counties | 1 | 1 | – | |
| 2016-01-01 | AvalancheKing County and Snohomish County · forecast zone Cascades Of Snohomish And King Counties | 1 | 0 | – |
Source: NOAA NCEI Storm Events Database, records through June 30, 2026; the newest months are revised by NCEI as reports arrive. Search the record at NCEI.
Federal disaster declarations for landslide and avalanche records in Washington
FEMA has declared 26 disasters in Washington for landslide and avalanche, counting its incident type and declarations that name landslide or mudslide in the title (FEMA files most storm disasters under Severe Storm); 24 were major disasters, the latest on April 7, 2026.
| Declared | Number | Title | Areas named |
|---|---|---|---|
| 2026-04-07 | DR-4906 | Severe Storms, Straight-Line Winds, Flooding, Landslides, and Mudslides | 49 |
| 2025-12-12 | EM-3629 | Severe Storms, Straight-Line Winds, Flooding, Landslides, and Mudslides | 17 |
| 2024-04-28 | DR-4775 | Severe Winter Storms, Straight-Line Winds, Flooding, Landslides, and Mudslides | 17 |
| 2023-01-12 | DR-4682 | Severe Winter Storm, Straight-Line Winds, Flooding, Landslides, and Mudslides | 9 |
| 2022-01-05 | DR-4635 | Severe Storms, Straight-Line Winds, Flooding, Landslides, and Mudslides | 12 |
| 2021-04-08 | DR-4593 | Severe Winter Storm, Straight-Line Winds, Flooding, Landslides, and Mudslides | 18 |
| 2020-04-23 | DR-4539 | Severe Storms, Flooding, Landslides, and Mudslides | 15 |
| 2019-03-04 | DR-4418 | Severe Winter Storms, Straight-Line Winds, Flooding, Landslides, Mudslides, Tornado | 8 |
| 2017-04-21 | DR-4309 | Severe Winter Storms, Flooding, Landslides, Mudslides | 15 |
| 2016-02-02 | DR-4253 | Severe Winter Storm, Straight-Line Winds, Flooding, Landslides, Mudslides, and A T | 10 |
| 2016-01-15 | DR-4249 | Severe Storms, Straight-Line Winds, Flooding, Landslides, and Mudslides | 16 |
| 2015-10-20 | DR-4243 | Wildfires and Mudslides | 9 |
Source: FEMA OpenFEMA Disaster Declarations Summaries (v2), through October 2, 2026. OpenFEMA dataset page.
Next
- Kitsap County: the county's whole recordThe Washington county with the most landslide and avalanche records per square mile
- Landslides and avalanches across the United StatesEvery state ranked, by year and month
- Every natural hazard in WashingtonTornadoes, floods, storms, heat and the federal declarations
- Winter storms in Washington4,060 records
- High wind and dust storms in Washington2,210 records
- Floods in Washington832 records