The Blue Cut Fire started burning late on Tuesday morning east of Los Angeles in the Cajon Pass. The blaze spread rapidly in dry and hot conditions.
The fire has burned at least 18,000 acres and is zero percent contained, according to InciWeb. The cause of the blaze is still unknown.
The fire poses an "imminent threat to public safety, rail traffic and structures" in the region, InciWeb warned early Wednesday morning.
More than 80,000 people were placed under mandatory evacuation orders due to the effects of the fire, including the entire town of Wrightwood, California.
Weather over the next several days will make it challenging for fire crews to gain ground containing the blaze.
"Very dry, very warm air will remain in place through at least Thursday with relative humidity dropping to less than 20 percent in many areas threatened by the Blue Cut Fire," AccuWeather Senior Meteorologist Dave Houk said.
Houk added that wind gusts will range from 25 to 35 mph that can fan the flames and create a dangerous situation for those battling the blaze.
Smoke from the fire was visible across the entire area and was also able detected on weather radar