Fueled by hot and dry weather, California’s largest fire has continued to balloon, prompting more orders for residents to flee their homes as officials warned that harsh conditions could persist for days.

The Dixie Fire in Northern California, which has been burning for more than three straight weeks, swelled to more than 274,000 acres on Wednesday and was 35 percent contained.

The Plumas County Sheriff’s Office issued mandatory evacuation orders Tuesday evening for Chester, Calif., which has a population of about 2,000, as well as Hamilton Branch and the Lake Almanor Peninsula, lakeside communities with resorts.

“Extreme fire behavior” was anticipated for Wednesday and an incident update noted “hot conditions will persist this afternoon across the fire area.” Officials warned of plummeting humidity in the afternoon and wind gusts up to 20 mph.

Ryan Walbrun, an incident meteorologist, said that as of Wednesday afternoon, a red-flag warning denoting high fire danger would go into effect for the “entire Dixie Fire area and actually much of the region.” The warning will run through Thursday evening.

“Some hazardous conditions are coming that will lend itself to additional fire growth,” Mike Wink, a Cal Fire operations section chief working on firefighting efforts, said during a briefing. “We have a plan, we’ve got the resources out there.”

The fire, which began July 13 and has scorched parts of Plumas and Butte counties, had been burning steadily in the past week, with thunderstorms bringing winds to the area. But in recent days, a pattern of extremely low humidity and high wind has intensified the blaze, which is threatening more populated areas.

“So many folks were affected by evacuations either again today or for the first time today,” Wink said. “Please make sure you have a plan.”

More than 7,400 people were under evacuation orders in three counties — Butte, Plumas and Tehama — as of Wednesday morning, according to the California governor’s office of emergency services, with a large majority forced to flee from Plumas County. In some areas of Butte and Plumas counties, evacuation orders were lifted over the weekend only to be reissued because of concerning conditions.

The communities around Lake Almanor are also home to dozens of families who were forced out of nearby Paradise, the town scorched by the deadly Camp Fire in 2018.

“We accepted that it could burn again,” Jack Montgomery, who moved to Chester after leaving Paradise, told The Washington Post last month, before evacuations were ordered but as the threat of the Dixie Fire loomed. “We just never thought it’d be this soon.”

Nearly 5,000 firefighters are battling the Dixie Fire — by far the largest burning in the state. The cause of the fire is under investigation, but the utility company Pacific Gas & Electric has said its equipment may be responsible for starting the blaze, as well as the smaller Fly Fire, which later merged with the Dixie Fire.

More than 12,000 buildings are threatened by the fire, with at least 67 structures already destroyed and nine damaged.

Firefighters were working Tuesday to protect homes and other buildings after crews spent Monday evening into Tuesday morning defending homes in Greenville, a community of about a thousand people.

“Stronger winds and instability” were forecast to challenge containment lines on Wednesday into Thursday “before a quiet weather pattern returns,” according to an incident report.

Late last month, the fire had grown so large and was burning so intensely that its smoke shaded itself, moderating conditions.

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