An explosive wildfire killed one person and left several others with burns after it tore through communities in northern California.

Flames swept across the rural areas of Shasta and Keswick on Thursday, before jumping the Sacramento River and reaching Redding, a city of around 92,000 people.

Late on Thursday, firefighters found the body of a bulldozer operator who was hired privately to clear vegetation in the blaze's path, CalFire spokesman Scott McLean said.

“[The fire is] taking down everything in its path,” he said. “It's just a wall of flames. It's non-stop.”

Three firefighters and an unknown number of civilians suffered burns during the fire, but information on the extent of their injuries was not immediately known.

“It's just chaotic. It's wild,” Mr McLean said: “There's a lot of fire, a lot of structures burning.”

The 45-square-mile fire that began on Monday tripled in size overnight on Thursday amid scorching temperatures, low humidity and windy conditions.

Wildfires throughout the state have burned through tinder-dry brush and forest, forced thousands to evacuate homes and forced campers to pack up their tents at the height of summer.

Governor Jerry Brown declared states of emergency for the three largest fires, which will authorise the state to rally resources to local governments.

Close to the town Idyllwild in southern California, helicopters continue to make water drops and air tankers pour red flame retardant on a blaze that started on Wednesday and now covers 7.5 square miles.

About 3,000 residents were under evacuation orders Thursday in the town and several neighbouring communities.

California wildfires: thousands flee homes after devastating blaze Show all 15 1 /15 California wildfires: thousands flee homes after devastating blaze California wildfires: thousands flee homes after devastating blaze Mandatory Credit: Photo by Neal Waters/ZUMA Wire/REX (9726569g) The Pawnee Fire in Lake County continued to show aggressive fire behavior in the early afternoon of Sunday. Fire crews focused on structure protection while helicopters make water drops to assist the strike teams on the ground. The Pawnee wildfire, California, USA - 24 Jun 2018 Neal Waters/ZUMA Wire/REX Rex California wildfires: thousands flee homes after devastating blaze An air tanker drops retardant on a wildfire above the Spring Lakes community on Sunday, June 24, 2018., near Clearlake Oaks, Calif. Wind-driven wildfires destroyed buildings and threatened hundreds of others Sunday as they raced across dry brush in rural Northern California. (AP Photo/Noah Berger) Noah Berger AP California wildfires: thousands flee homes after devastating blaze Mandatory Credit: Photo by Neal Waters/ZUMA Wire/REX (9726569v) The Pawnee Fire in Lake County near the communities of Clearlake Oaks and Spring Valley has burned over 1000 acres by 4am Sunday The Pawnee wildfire, California, USA - 24 Jun 2018 Fire crews focused on structure protection while helicopters make water drops to assist the strike teams on the ground. The fire started late Saturday evening and was driven by low humidity, high temperatures and gusty winds. Neal Waters/ZUMA Wire/REX Rex Features California wildfires: thousands flee homes after devastating blaze Fire crews battle a wildfire near Cache Creek Road in Spring Valley, Calif., Monday, June 25, 2018. Thousands were forced to flee their homes Monday as major wildfires encroached on a charred area of Northern California still recovering from severe blazes in recent years, sparking concern the state may be in for another destructive series of wildfires this summer. (Paul Kitagaki Jr./The Sacramento Bee via AP) Paul Kitagaki Jr. AP California wildfires: thousands flee homes after devastating blaze A structure leveled by a wildfire rests in a clearing on Wolf Creek Road near Clearlake Oaks, Calif., on Sunday, June 24, 2018. Wind-driven wildfires destroyed buildings and threatened hundreds of others Sunday as they raced across dry brush in rural Northern California. (AP Photo/Noah Berger) Noah Berger AP California wildfires: thousands flee homes after devastating blaze Mandatory Credit: Photo by Neal Waters/ZUMA Wire/REX (9726569m) The Pawnee Fire in Lake County continued to show aggressive fire behavior in the early afternoon of Sunday. Fire crews focused on structure protection while helicopters make water drops to assist the strike teams on the ground. The Pawnee wildfire, California, USA - 24 Jun 2018 Neal Waters/ZUMA Wire/REX Rex Features California wildfires: thousands flee homes after devastating blaze A vehicle scorched by a wildfire rests in a clearing on Wolf Creek Road near Clearlake Oaks, Calif., Sunday, June 24, 2018. Wind-driven wildfires destroyed buildings and threatened hundreds of others Sunday as they raced across dry brush in rural Northern California. (AP Photo/Noah Berger) Noah Berger AP California wildfires: thousands flee homes after devastating blaze Cal Fire battles a wildfire in Spring Valley, Calif., Sunday, June 24, 2018. Wind-driven wildfires destroyed buildings and threatened hundreds of others Sunday as they raced across dry brush in rural Northern California. (Paul Kitagaki Jr./The Sacramento Bee via AP) Paul Kitagaki Jr. AP California wildfires: thousands flee homes after devastating blaze Firefighters work to contain a wildfire in Spring Valley, Calif., Sunday, June 24, 2018. Wind-driven wildfires destroyed buildings and threatened hundreds of others Sunday as they raced across dry brush in rural Northern California. (Paul Kitagaki Jr./The Sacramento Bee via AP) Paul Kitagaki Jr. AP California wildfires: thousands flee homes after devastating blaze In this photo provided by the California Department of Forestry and Fire Protection, the Pawnee Fire wildfire burns northeast of Clearlake Oaks, Calif., early Sunday, June 24, 2018. The Pawnee Fire, which broke out Saturday, was one of four wildfires burning in largely rural areas as wind and heat gripped a swath of California from San Jose to the Oregon border. (Jonathan Cox/California Department of Forestry and Fire Protection via AP) Jonathan Cox AP California wildfires: thousands flee homes after devastating blaze Cal Fire battles a wildfire on Sunday, June 24, 2018 in Spring Valley, Calif. Wind-driven wildfires destroyed buildings and threatened hundreds of others Sunday as they raced across dry brush in rural Northern California. (Paul Kitagaki Jr./The Sacramento Bee via AP) Paul Kitagaki Jr. AP California wildfires: thousands flee homes after devastating blaze In this photo provided by the California Department of Forestry and Fire Protection, the Pawnee Fire wildfire burns in the Spring Valley area, northeast of Clearlake Oaks in Lake County, Calif., early Sunday, June 24, 2018. The Pawnee Fire, which broke out Saturday near Clearlake Oaks, was one of four wildfires burning in largely rural areas as wind and heat gripped a swath of California from San Jose to the Oregon border. (Jonathan Cox/California Department of Forestry and Fire Protection via AP) Jonathan Cox AP California wildfires: thousands flee homes after devastating blaze In this photo provided by the California Department of Forestry and Fire Protection, the Pawnee Fire wildfire burns northeast of Clearlake Oaks, Calif., early Sunday, June 24, 2018. The fire burned actively throughout the night in the Spring Valley area, northeast of Clearlake Oaks in Lake County. The Pawnee Fire, which broke out Saturday, was one of four wildfires burning in largely rural areas as wind and heat gripped a swath of California from San Jose to the Oregon border. (Jonathan Cox/California Department of Forestry and Fire Protection via AP) Jonathan Cox AP California wildfires: thousands flee homes after devastating blaze Cal Fire helicopter helps battle a wildfire in Spring Valley, Calif., Sunday, June 24, 2018. Wind-driven wildfires destroyed buildings and threatened hundreds of others Sunday as they raced across dry brush in rural Northern California. (Paul Kitagaki Jr./The Sacramento Bee via AP) Paul Kitagaki Jr. AP California wildfires: thousands flee homes after devastating blaze An air tanker drops retardant on a wildfire burning above the Spring Lakes community on Sunday, June 24, 2018, near Clearlake Oaks, Calif. Wind-driven wildfires destroyed buildings and threatened hundreds of others Sunday as they raced across dry brush in rural Northern California. (AP Photo/Noah Berger) Noah Berger AP

The blaze, which has been named Cranston Fire, was the largest of at least five police believe were purposely set by a man whose car was spotted at the starting point of the blaze in Riverside County, officials said.

Brandon McGlover, 32, of Temecula has been arrested on suspicion of five counts of arson, state fire officials said.

Meanwhile, Yosemite National Park remained empty the day after campers and hotel guests were evicted so firefighters could try to keep the state's largest fire from entering the park nearly two weeks after it was sparked.

Officials insisted Yosemite wasn't in imminent danger from the Ferguson Fire, which grew to more than 67 square miles in steep timber in the adjacent Sierra National Forest. The fire remains only 25 per cent contained.