Northern California's McKinney fire is state's largest blaze this year

The McKinney fire in Northern California is now the largest to break out in the state this year.

The fire started around 2:38 p.m. on Friday, and as of Sunday morning, it has burned more than 51,468 acres in the Klamath National Forest. The blaze is 0 percent contained, and has burned down several houses and is threatening hundreds of others. Officials said there are 650 firefighters on the scene, and they are prioritizing protecting Yreka, Fort Jones, and other communities in the Highway 96 corridor. The cause of the fire is under investigation.

Caroline Quintanilla, a spokesperson for the U.S. Forest Service, said the "particular area where the fire is actually burning right now has not burned since the mid-'50s. So that's part of the concern as well, and part of their complexity, because it hasn't burned in a long time."

Firefighters had to battle both the flames and the heat on Sunday, with the temperature hovering around 100 degrees. "The fire becomes more energetic, and the potential for fire increases ... when temperatures warm up like that," National Weather Service meteorologist Jonathan Garner told the Los Angeles Times.