California has never before seen a fire as large as the one burning now on federal land north of Sacramento.

The California Department of Forestry and Fire Protection, or Cal Fire, on Thursday put the August Complex Fire in Mendocino National Forest atop its list of the largest wildfires in the state. Six of the 20 largest fires have taken place this year.

Gov. Gavin Newsom, who has blamed climate change for the current crop of fires, said Thursday that 2.6 million acres have burned in California this year. Cal Fire officials updated the number to 3.1 million Thursday afternoon.

The August Complex Fire is a combination of 37 fires sparked by lightning in Mendocino National Forest on Aug. 17, the U.S. Forest Service said in a statement. It has so far burned 471,185 acres and is 24 percent contained.

Forest Service spokesman Terry Krasko suggested that the fire may actually be bigger. He said an airplane with infrared capabilities that measure the size of a blaze was out of service Thursday.

The fire became known as the August Complex Fire about five days ago, when numerous blazes combined, Krasko said. Many smaller fires have been extinguished, he said, but larger parts of the fire, including the Doe Fire, continued to grow Thursday afternoon