SAN FRANCISCO -- In a year that has already brought apocalyptic skies and smothering smoke to the West Coast, California set a grim new record Sunday when officials announced that the wildfires of 2020 have now scorched a record 4 million acres -- in a fire season that is far from over.

The unprecedented figure -- an area larger than the state of Connecticut -- is more than double the previous record for the most land burned in a single year in California.

"The 4 million mark is unfathomable. It boggles the mind, and it takes your breath away," said Scott McLean, a spokesman for the California Department of Forestry and Fire Protection, known as Cal Fire. "And that number will grow."

So far, in this year's historic fire season, more than 8,200 California wildfires have killed 31 people and scorched "well over 4 million acres in California" or 6,250 square miles, Cal Fire said Sunday in a statement. The blazes have destroyed more than 8,400 buildings.

The astonishing figure is more than double the 2018 record of 1.67 million burned acres (2,609 square miles) in California. All large fire years since Cal Fire started recording figures in 1933 have remained well below the 4 million mark -- "until now," the agency said Sunday in a Tweet.

"This year is far from over and fire potential remains high. Please be cautious outdoors."

The enormity of the fires has meant that people living far from the flames experienced a degree of misery that in itself was unprecedented, with historically unhealthy air quality and smoke so dense that it blurred the skies across California and on some days even blotted out the sun. Last month, a relentless heat wave hit the state that helped fuel the fires and caused so much air pollution that it seeped indoors, prompting stores across California to sell out of air purifiers.

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."

Despite Sunday's grim milestone, there were signs for optimism.

Powerful winds that had been expected to drive flames in recent days hadn't materialized, and warnings of extreme fire danger for hot, dry and gusty weather expired Saturday morning as a layer of fog rolled in. Clearer skies in some areas allowed large air tankers to drop retardant after being sidelined by smoky conditions several days earlier.

"In certain areas, we were able to get quite a bit of aircraft in. So we really pounded, a couple different areas hard with aircraft," Mclean said. "If the weather does what is predicted, we're on that glide path I hope. But that doesn't diminish the amount of work that still needs to be done."

Long-range forecast models hinted at the possibility of rain early in the week.

Fire officials said the Glass Fire burning in wine country for the past week was their top priority. Easing winds over the weekend proved a mixed blessing for firefighters battling the giant blaze, which is currently 17 per cent contained.

"We are seeing some relief in the weather, but it's going to be three of four days before it really makes a difference on the fire," Cal Fire meteorologist Tom Bird said at a Sunday news briefing about the Glass Fire. "The one good thing going forward, we're not expecting any wind events to push into the fire."

The Glass Fire began last Sunday as three fires merged and drove into vineyards and mountain areas, including part of the city of Santa Rosa. More than 30,000 people were still under evacuation orders this Sunday, down from 70,000 earlier in the week. Among those still unable to return home are the entire 5,000-plus population of Calistoga in Napa County.

Across the state about 17,000 firefighters were at work battling nearly two dozen major blazes.

Virtually all the damage has occurred since mid-August, when five of the six largest fires in state history erupted. Lightning strikes caused some of the most devastating blazes. The wildfires have incinerated hundreds of homes and killed 31 people but large parts of them are burning in largely unpopulated land.

Many of the most destructive fires sparked in Northern California, where hills and mountains dotted with many dead trees have provided plenty of fuel for fires igniting amid high temperatures and strong winds fanning the flames. Thick, gray smoke from the blazes has fouled the air in many hill communities and major cities in the San Francisco Bay Area and beyond.

Flannigan, the fire scientist, estimates the area of land burned from wildfires in California has increased fivefold since the 1970s.

"Temperature is really important to fire. Temperature is key. The warmer it is, the longer the fire season," he said.

"This is an unprecedented year and the thing is there's no vaccine for wildfires," Flanigan said. "We're going to have to learn to live with wildfires and the associate smoke."

------

Associated Press writer Olga R. Rodriguez contributed to this report.