Light rain is falling in some areas of Northern California, where the deadly Camp Fire has been burning for nearly two weeks, the AP reported.
Moderate rain is expected later Wednesday in the Paradise burn area, where a wildfire killed at least 83 people and destroyed more than 13,000 homes.
There are 563 people still missing or unaccounted for.
The 153,336-acre Camp Fire burning across Butte County is now 85 percent contained.
Rain forecast through the Thanksgiving weekend could aid crews fighting wildfires while complicating efforts to recover human remains.
The National Weather Service issued a flash flood watch, saying brief periods of heavy rain could unleash mudslides.
Rain is also expected along the central coast and in Southern California later in the day.