Fuelled by wind and dry conditions, the Caldor Fire burning in El Dorado county in Northern California has scorched 65,474 acres of land so far, and grew 10 times in size in just 48 hours, according to Inciweb, an interstate incident information system.
According to Inciweb, spotting and rollout continued to be the main contributor to fire spread throughout Wednesday evening and multiple new spot fires were expected on Thursday, so the blaze sparked on August 14 had potential to grow further, reports Xinhuaa news agency.
The latest data released by the California Governor's Office of Emergency Services on Thursday revealed that 25,000 people had been evacuated in El Dorado county due to the fast-moving fire.
There are 653 firefighters battling the fire, which is zero percent contained.
As of Thursday, the California Department of Forestry and Fire Protection (Cal Fire) said 86 structures had been confirmed destroyed by the fire and nearly 7,000 structures remain threatened.
Meanwhile, the Dixie Fire, California's second-largest in history which has been active for more than a month, also swelled more than 60,000 acres in two days.
It prompted a new round of evacuation orders on Wednesday as gusty winds helped spread the fire within about 15 km of Susanville, a town with 15,000 residents.
The Dixie Fire, the nation's largest active fire, burned down 678,369 acres with 35 percent containment as of Thursday, about three times the size of Manhattan.
It had destroyed more than 1,200 structures, including 645 single residences, Cal Fire said.
At least 16,085 structures were still threatened by the flames.
Three first responders had been injured fighting the fire, according to officials.
Cal Fire Director Thom Porter said Wednesday that the Dixie Fire was the first wildfire burned across the range of Sierra Nevada in history.
"The Dixie Fire is the first fire that we're aware of that has burned from the west side of the mountain range all the way over and to the valley floor on the east side of the mountain range. We don't have any record of that happening before," Porter said.
"It is exceedingly resistant to control."
