MENDOCINO COUNTY (CBS SF/AP) — A lightning spark wildfire, burning mostly in wilderness areas of seven Northern California counties, grew to more than 1 million acres Monday — the largest fire in California state history and spanning an area equal to the size of the state of Rhode Island.

The blaze was ignited by dry lightning strikes in the Mendocino National Forest on August 16th and has burned in Mendocino, Humboldt, Trinity, Tehama, Glenn, Lake and Colusa counties. On Monday, dozens of areas remained under evacuation orders in both Trinity and Mendocino counties.

As of Monday, it covered nearly 1,566 square miles. There were 1,691 firefighters on the line from Cal Fire and fire departments from throughout California and the nation.

Lightning strikes during that same nearly unprecedented storm also triggered the SCU Lightning Complex Fire (the state’s third largest wildfire outbreak in state history), the LNU Lightning Complex Fire (the fourth largest outbreak) and the CZU Complex Fire in the Santa Cruz Mountains.

So far this summer, firefighters have battled five of the sixth largest wildfire outbreaks in California history.

Since the beginning of the year, more than 8,200 California wildfires have scorched “well over 4 million acres” or 6,250 square miles, the California Department of Forestry and Fire Protection said Sunday in a statement. There have been 31 deaths and more than 8,400 buildings have been destroyed.

Numerous studies have linked bigger wildfires in America to climate change from the burning of coal, oil and gas. Scientists say climate change has made California much drier, meaning trees and other plants are more flammable.

Mike Flannigan, who directs the Canadian Partnership for Wildland Fire Science at Canada’s University of Alberta, says the escalation of fires in California and the U.S. West is “largely, not solely, due to human-caused climate change.”

The August Complex has destroyed 242 structures and damaged a half dozen. One firefighter has died and one has been injured. Containment was estimated at 54% on Monday.

California remains largely warm and dry but fierce winds that fanned infernos a week ago were gone. Cooling at the coast was expected to expand into the interior and a Pacific storm system remained in the forecast for Northern California by next weekend.