As hot and dry conditions persist in parts of Southern California, fire crews are continuing their battle against the Route Fire near Castaic Monday.

The fire erupted Saturday afternoon near the 5 Freeway and Templin Highway, eventually jumping the freeway and threatening structures as it consumed hundreds of acres on dry hillsides over the weekend.

“The first units on scene immediately reported that the fire was spotting on the west side of Interstate-5, so essentially we had two fires going,” Forest Service spokesman John Miller said.

The blaze held at 462 acre overnight with containment still at 63% Monday morning, according to Angeles National Forest officials.

On Saturday, California Highway Patrol closed both sides of the 5 Freeway at State Route 138 and Templin Highway as the fire raged.

Fire crews attacked the fire from the ground and the air, making drops on the flames throughout the night. By Sunday, fire officials were reporting making good progress battling the blaze.

CHP reopened southbound lanes of I-5, with plans to reopen all northbound lanes at 7 p.m. Monday.

While officials said an unknown number of structures were threatened by the blaze, no evacuation warnings were issued for the area.

Meanwhile, the region was experiencing critical fire conditions through Monday, with valley, mountain and desert areas potentially getting temperatures of up to 100 degrees amid gusty onshore winds, according to the National Weather Service.

The conditions mean that any flames that spark will grow quickly.

Residents were urged to avoid prolonged exposure to heat and avoid fire-related activities.

“With the continued hot weather, low relative humidity, and wind, you know, and then you couple that with the drought that we’ve been experiencing, Southern California really is moving into the peak of its fire season,” Miller said.