Firefighters have reached 25% containment against the fast-moving Canyon fire, which exploded to nearly 5,000 acres late Thursday, forcing thousands to evacuate.

Temperatures in the area are near 100 degrees and humidity as low as 15 percent. The southern part of California has seen very little rain, drying out vegetation and making it "ripe to burn," the National Weather Service (NWS) for Los Angeles warned.

Fire officials say the blaze is threatening power lines as well as the communities of Hasley Canyon and Hathaway Ranch.