Sizzling heat is exacerbating the fire risks out West on Monday, where weary crews have been battling blazes in Utah, Nevada, Oregon and California.
"Red flag warnings continue over parts of the West," CNN meteorologist Dave Hennen reported. "Critical fire danger and critical fire risk continue to cover large areas in the West."
About 16 million people remain affected by heat warnings and advisories in southern California, southern Nevada and parts of Arizona.
In the big metro areas of Phoenix and Las Vegas, temperatures are expected to be above 110 degrees. That would be 10 days in a row for such temperatures in Las Vegas.
Relief could be coming.
"Cooler weather is expected to push into the Southwest over the next few days," Hennen said.
Utah fires rage
Utah caught a bit of a break on Sunday but has a challenge ahead.
"Winds will increase over the fire area today, and scattered storms could bring lightning and erratic gusty winds," Hennen said.
The Utah Division of Forestry, Fire and State Lands said Sunday that 1,140 personnel were now fighting the massive Brian Head Fire that started June 17.
The fire has burned 43,436 acres and is just 10% contained, with the agency estimating that it will take until July 15 to get it fully under control.
Ten communities have been evacuated.
While firefighters made good progress over the weekend, Monday is a "red flag day," Bear Head Fire spokeswoman Elayn Briggs told CNN. That's due to a small system of erratic wind expected in the area in the afternoon, which would push the fire to the northwest. As a precaution, the region to the northwest of the fire, a remote area called Upper Bear Valley, has been evacuated, she said.
"Horse Valley will be an area of concern (Monday), but crews have begun to prepare for this using dozers and retardant dropped from air tankers to establish indirect firelines," Brian Head town said on its Facebook page.
At least 13 homes and eight outbuildings have been destroyed in the ski town, which sits near the Dixie National Forest in the southern part of the state.
Hundreds battle Arizona wildfire
The Frye Fire in southern Arizona covered more than 37,000 acres as of Sunday, with 39% of the perimeter contained, the forest service at Coronado National Forest said.
More than 900 personnel are battling the fire, which started June 7. The Frye Fire is about 70 miles northeast of Tucson, the second-largest city in Arizona.
Gov. Doug Ducey declared a state of emergency Friday in Arizona to authorize the use of $200,000 of emergency funds to counter increased wildfire activity.
Since April, the state has experienced more than a dozen large wildfires "aided by high temperatures, winds, and available fuels," his office said in a statement.
"We thank the many brave men and women who have stepped up and responded to wildfires around Arizona," Ducey said. "I'm issuing today's declaration to make sure they have every resource needed to do their jobs and protect our communities."
The area near the fire is expecting temperatures in the triple digits through next Friday, with no sign of rain.
Fire in rural LA county
A fire sparked by a traffic collision in California's Placerita Canyon is the latest blaze to hit the West amid a deadly heatwave.
The Los Angeles County Sheriff's Department said the collision Sunday caused a tree to catch on fire, beginning a blaze that spread toward the Disney Ranch area.
Sheriff's deputies began helping residents of the Disney Ranch, Tenderfoot Trail Road, Running Horse Road and Placerita Canyon areas to evacuate and affected residents were told to seek shelter at Golden Valley High School in Santa Clarita.
By Sunday evening, the fire had grown to 870 acres, with 50 percent containment, according to Los Angeles County Fire Department.
Evacuation orders that had been issued earlier Sunday were lifted later in the evening.
The US Forest Service has reported that at least 13 large wildfires are burning across the western United States with more reported smaller ones across the region. Two of the largest are in southern Arizona and Utah.
Wildfires already have caused far more destruction than usual in the first half of 2017, meteorologist Haley Brink of the CNN Weather Center said. Almost 1 million more acres had burned by Thursday, compared with the 10-year average through June 22.
There are also smaller blazes in other states.
In New Mexico, the Corral Fire reached about 17,000 acres and is burning with low to moderate intensity, according to New Mexico Fire Information.
Meanwhile, in central Oregon, the Rhoades Canyon Fire grew to 15,000 acres but was 100% contained Sunday.
The heat in the West and Southwest is blamed for the deaths of two people in California, and it could have been a factor in the deaths of two hikers whose bodies were found in New Mexico's Carlsbad Caverns National Park.
CNN's Michael Guy, Nicole Chavez, Eric Levenson, Tony Marco and Samira Said contributed to this report.
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