The August Complex was a massive wildfire that burned in the Coast Range of Northern California, in Glenn, Lake, Mendocino, Tehama, Trinity, and Shasta Counties. The complex originated as 38 separate fires started by lightning strikes on August 16–17, 2020. Four of the largest fires, the Doe, Tatham, Glade, and Hull fires, had burned together by August 30. On September 9, the Doe Fire, the main fire of the August Complex, surpassed the 2018 Mendocino Complex to become both the single-largest wildfire and the largest fire complex in recorded California history. On September 10, the combined Doe Fire also merged with the Elkhorn Fire and the Hopkins Fire, growing substantially in size. By the time it was extinguished on November 12, the August Complex fire had burned a total of 1,032,648 acres (417,898 ha), or 1,614 square miles (4,180 km2), about 1% of California's 100 million acres of land, an area larger than the state of Rhode Island.

The Mendocino Complex Fire was a large complex of wildfires that burned in northern California for more than three months in 2018. It consisted of two wildfires, the River Fire and Ranch Fire, which burned in Mendocino, Lake, Colusa, and Glenn Counties in the U.S. State of California, with the Ranch Fire being California's single-largest recorded wildfire at the time until the Dixie Fire in 2021. The Ranch Fire burned eight miles northeast of Ukiah, and the River Fire burned six miles north of Hopland, to the south of the larger Ranch Fire. First reported on July 27, 2018, both fires burned a combined total of 459,123 acres (1,858 km2), before they were collectively 100% contained on September 18, though hotspots persisted until the complex was fully brought under control on January 4, 2019. The Ranch Fire alone burned 410,203 acres (1,660 km2), making it the largest wildfire in modern California history at the time until the August Complex fire that occurred in 2020. The Ranch Fire also surpassed the size of the 315,577-acre Rush Fire, which burned across California and Nevada, as well as the Santiago Canyon Fire of 1889, which was previously believed to have been California's all-time largest wildfire.