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

A brush fire started on a sweltering day east of Lake Piru in Ventura County and led to evacuations as this week’s warm temperatures in Southern California reached their peak. The Canyon Fire was estimated at about 50 acres early Thursday afternoon before quickly spreading to more than 4,

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.