The National Weather Service warned Saturday night about the risk of landslides overnight and into midday Sunday.
The Weather Service reported that continuing heavy rain will add to the problem of already saturated soils, which could weaken steep hillsides and waterfront bluffs.
Rainfall over the past week had already triggered landslides near Auburn and Mukilteo, the Weather Service reported.
Parts of State Highway 12 across White Pass were closed Saturday night due to a mudslide. State highway crews were expected to check the road after daylight on Sunday.
More landslides are possible in the coming days, the Weather Service said.
A flood watch was also posted for late Saturday through late Sunday for much of Western Washington, including Pierce, Thurston and King Counties.