LOS ANGELES — The total acres burned in California this year surpassed 1 million as spiking temperatures Tuesday added to the challenges facing firefighters struggling to contain a stubborn blaze in the mountains northeast of Los Angeles that flared up over the weekend.

Evacuation orders were expanded again Monday for remote communities northeast of Los Angeles as the Line Fire that has been burning for nearly a month spread over nearly 68 square miles of the San Bernardino Mountains and containment dropped from 83% to 76%.

“The dry vegetation, steep slopes and wind aligned ... to create conditions for the rapid fire spread,” according to a statement late Monday from the California Department of Forestry and Fire Protection, or Cal Fire.

The risk of wildfires increased across California as an autumn heatwave scorched much of the state. Some inland areas could see temperatures up to 20 degrees above average for this time of year, according the National Weather Service.

San Francisco, where residents typically break out the sweaters in October, could hit 90 degrees, while triple digits were predicted for Sacramento. The weather service office in the state’s capital urged residents to stay indoors during the heat of the day Tuesday.

Dry, hot winds in the northern part of the state prompted Pacific Gas & Electric to preemptively cut power to small clusters of customers in high-risk areas. The utility routinely stops electricity service in counties where weather conditions increase the probability of fires.

In Southern California, the Line Fire’s surge pushed the total acres burned across the state in 2024 to 1,001,993 as of Tuesday morning, according to Cal Fire. The milestone surpasses the total scorched during the same time last year — 293,362 acres — but is roughly on par with the five-year average for the period, the Los Angeles Times reported.

A 34-year-old man has pleaded not guilty to starting the Line Fire on Sept. 5. Justin Wayne Halstenberg of Norco, California, was charged with 11 arson-related crimes, according to court records.

At its height, the blaze threatened more than 65,000 homes in and around the Big Bear Lake area.