A thick blanket of dark smoke lies over the entire area.
The fire, which is around 7,000 hectares in size, started on Thursday and is still raging in the San Bernardino national park. Over 600 firefighters are battling the flames that threaten more than 35,000 buildings.
The fire burned so intensely over the weekend that it created its own thunderstorm-like weather system, according to the US Meteorological Organization National Weather Service. This risks leading to strong gusts of wind and lightning strikes – which could further worsen the situation.
The firefighters are already struggling in the steep terrain, which makes it harder to get the flames under control. The authorities have ordered the evacuation of several nearby towns.
The risk of losing our home and everything we've worked so hard for is terrifying, says Joseph Escobedo, who lives in Angelus Oaks outside Los Angeles, to AP.
He and his family were some of the few remaining who had not yet evacuated on Sunday afternoon, local time.
It's hard to leave and not know if we'll be able to come back, says Escobedo as he and his family pack up the essentials to flee the flames and smoke.
Meanwhile, around 4,000 people were forced to evacuate their homes in Clearlake, 117 kilometers north of San Francisco, after a small forest fire that started on Sunday afternoon spread. About 30 homes and commercial buildings had caught fire by then.