Fire stoked by hot and windy weather has raged through a forest in far northern California.
In mountain communities east of Los Angeles, calmer conditions aided firefighters on the lines of a suspected arson wildfire that forced thousands of people to flee.
California Governor Jerry Brown on Thursday issued emergency proclamations in both Riverside County in the south and Shasta County in the north. The declarations authorise the state to rally resources to local government.
In the north, new evacuations were ordered for communities in the wilderness recreation region near Whiskeytown Lake as that wildfire tripled in size to more than 80 square kilometres.
It had already forced residents out of French Gulch, a hamlet dating to the Gold Rush.
California Fire Unit Chief Mike Hebrard told the Record Searchlight newspaper that the blaze made a huge push overnight and that engine crews were in the community of Old Shasta trying to save structures.
Hundreds of kilometres to the south, winds were absent over the fire in Southern California’s San Jacinto Mountains.
Local weather forecasters said temperatures were rapidly rising, and may hit 38C with possible afternoon wind gusts that could create dangerous fire conditions.
Elsewhere in the state, a huge forest fire continued to grow outside Yosemite National Park.
A total of 100 homes were still considered under threat in the San Francisco Bay community of Clayton, although firefighters had stopped the progress of a small fire there after one house burned.
About 3200 people in the town of Idyllwild and nearby communities were ordered to evacuate. An estimated 600 homes were threatened.
The fire was the largest of at least five that police believe were purposely lit on Wednesday by a man whose car was reportedly spotted at the starting point of the blaze in Riverside County, officials said.