Residents in nearly 200 homes in a subdivision in the county's Pope Valley were allowed to return after an evacuation order was lifted Thursday afternoon.
Neither fire has led to any injuries. The causes of both remained unknown.
Also Friday, a water park and other recreations areas were evacuated and a minor league soccer game was canceled after a brush fire broke out near the Cal Expo state fairgrounds in Sacramento and burned about 40 acres.
Firefighters had it contained about four hours after it started and in time to save Cal Expo's annual fireworks celebration.
In northwest Nevada, fire officials said a wildfire sparked by lightning was threatening several ranches and critical sage grouse habitat.
The blaze, which started Tuesday, was burning about 25 miles northeast of Fort Bidwell, California, and 3 miles south of the Oregon line. It has charred more than 14 square miles of remote rangeland managed by the U.S. Bureau of Land Management.