Wildfire Erupts in Orange County, Forcing Evacuations

A brush fire that erupted on Monday afternoon in the hills of Orange County in Southern California exploded to more than 5,000 acres within a few hours, prompting evacuation orders for nearby communities as the blaze burned uncontrolled.

Known as the Airport fire, it began just before 1:30 p.m. about 15 miles east of Irvine, Calif., near an airport for remote-controlled model airplanes. Officials ordered evacuations in parts of Trabuco Canyon, a community in the foothills of the Santa Ana Mountains, and recommended evacuations for surrounding neighborhoods.

The fire broke out during a prolonged heat wave that has pushed temperatures in many parts of Southern California into the triple digits in recent days. It was one of several threatening the region on Monday night.

A brush fire in Los Angeles County, known as the Bridge fire, grew to nearly 3,000 acres on Monday, a day after breaking out in the Angeles National Forest. It was 0 percent contained as of Monday evening.

Another blaze, the Line fire, began on Thursday in the foothills of the San Bernardino Mountains, about 55 miles northeast of Trabuco Canyon. As of Monday night it had swelled to threaten more than 38,000 structures and was only 5 percent contained.

In Trabuco Canyon, temperatures reached about 98 degrees Fahrenheit on Monday, above normal for early September, said Samantha Zuber, a meteorologist with the National Weather Service in San Diego. Wind speeds were about 15 miles per hour, she said.

The winds were expected to slow into the evening, but overnight temperatures will remain unusually high, unlikely to drop below 70 degrees, she said. Similar conditions have been fueling wildfires in the state all summer. “Unfortunately, temperatures won’t cool that much,” Ms. Zuber said.

She said that temperatures in the fire zone would begin to drop on Tuesday — a high of 95 is expected — before a significant cool down, which is forecast to start on Wednesday and continue for the rest of the week.

The blaze started in a rural area where narrow roads and single-family homes are tucked in the midst of steep, brushy canyons. It’s a popular area for hiking and riding motorcycles. The canyons quickly give way to gated communities full of expensive homes that offer close access to nature. The area also features strip malls and wide, well-maintained streets.

Eric Nelson, the president of Trabuco Flyers, which oversees a flying field for remote-controlled airplanes, said the fire appeared to have begun on a neighboring property. So far, the winds are blowing away from the flying field, where on weekends as many 120 people gather to fly remote-controlled planes.

“Let’s keep praying the wind doesn’t shift and start coming out of the east — then we’ll be in trouble,” said Mr. Nelson, who added that high temperatures had kept people away from the field in recent days. “My goodness, we’ve had quite a hot spell.”

Jessica Clemente and her family went to the Rancho Santa Margarita community center late Monday afternoon because their home in Trabuco Hills was in an evacuation area. As she picked up her children from their schools, her husband walked a mile and a half on closed roads back to their house to grab clothes, a computer and chargers for what they anticipate will be a two-night stay in an Airbnb rental.

Their children — Joaquin, 5, and Ximena, 3 — had other priorities.

“They asked if their toys are going to be safe,” Ms. Clemente said.

Farther north, another major blaze has prompted thousands of evacuations in Northern Nevada and was problematic enough to force the Harris-Walz campaign to cancel a scheduled rally on Monday. Gov. Tim Walz of Minnesota had been scheduled to headline an event in Reno, Nev., but instead spoke to volunteers at a local field office and met with emergency workers.

Mr. Walz kept his short remarks focused on the fire, but the Nevada Republican Party argued on X that the campaign was “using a current wildfire crisis as a political ploy.”

California has already had a difficult start to the fire season after two consecutive wet winters led to heavy vegetation growth across the state. Scorching temperatures this summer have parched the bounty of grasses and brush, which have turned into abundant dry fuel.

The Park fire, which ignited on July 24 in Chico, Calif., quickly ballooned into the fourth-largest fire in California history, spreading across more than 429,000 acres. That fire alone has burned more acres than all of the fires in California did last year combined, according to the California Department of Forestry and Fire Protection.

Jill Cowan contributed reporting from Los Angeles, Victoria Lim from Rancho Santa Margarita, Calif., and Kellen Browning from Reno, Nev.