What is the location of the flooding?
On December 11, 2025, there is widespread, dangerous flooding in most of western Washington State, northern Idaho, and northwest Montana (1). There are flood warnings, flood advisories, flood watches, and flash flood watches across the region (2).
As many as 100,000 people may need to evacuate across Washington State (3). That number includes everyone in the Skagit River 100-year floodplain. Over the past 72 hours, an estimated 10 to 18 inches of rain have fallen across the Olympic and Cascade mountain ranges.
Southern British Columbia, Canada is also experiencing flooding, where most major highways leading to Vancouver have been closed (4).
Flooding impacted rivers and creeks in southwestern Oregon earlier in the week (5). Strong winds toppled trees, causing power outages across the region.
Rain is likely to subside by late Friday evening and into Saturday morning but is likely to return on Sunday (6).
Which cities or areas are affected by the flooding?
Pacific Northwest cities affected by the flooding include:
-
Bellingham, Washington
- Concrete, Washington
- Everett, Washington
- Hamilton, Montana
- Olympia, Washington
- Port Angeles, Washington
- Seattle, Washington
- Tacoma, Washington
- Vancouver, British Columbia
- Yakima, Washington
Are there any evacuation orders or alerts in place?
Evacuations are underway in Skagit, Whatcom, Snohomish, Pierce counties, Washington. There are "GO NOW" level three evacuation orders for these towns in Washington State (7):
- Burlington
- La Conner
- Lyman
- Hamilton
- Mount Vernon (some areas)
- Sedro-Wooley
A state of emergency has been declared for Washington State by Governor Bob Ferguson (8). Amtrak has stopped service between Seattle and Vancouver.
In Oregon, flood warning will remain in effect for Clackamas and Marion counties until Thursday evening (9).
How can I protect myself from mold after flooding?
It’s important to take steps to prevent mold after a flood.
- Before entering a flooded area, make sure it is safe and free from electrical hazards or structural damage.
- Use protective gear: wear gloves, goggles, and a KN95/FFP2 mask to minimize exposure to mold spores.
- If there is still standing water, remove it as quickly as possible. Use pumps, wet-dry vacuums, or buckets to extract the water.
- Open windows and doors to facilitate air circulation and use fans, dehumidifiers, and HVAC systems to help dry the space. This step is crucial within the first 24-48 hours after flooding to prevent mold growth.
- Remove and discard any items that have been severely damaged by floodwater and cannot be thoroughly cleaned and dried. This includes carpets, upholstered furniture, mattresses, and any other porous materials.
- Thoroughly clean all hard surfaces with a detergent or cleaner suitable for mold remediation. Use a solution of 1.5 cups of bleach mixed with one gallon of water to disinfect nonporous surfaces. Never mix bleach with ammonia or other cleaning products, as the fumes are toxic.
- Maintain an indoor relative humidity (RH) of 35-50%. High humidity promotes mold growth, so consider using dehumidifiers in damp areas.
- Run a high-performance air purifier for mold, both during and after the mold removal work.
- If the flooding and mold damage are extensive, consider contacting professionals specializing in mold remediation to ensure proper cleanup and restoration.
Remember, mold can pose health risks, so it's important to take these steps promptly and thoroughly. If you experience persistent mold-related health issues or have concerns about extensive mold growth, consult with a medical professional or a mold remediation specialist.
