LOS ANGELES — Authorities in Western states warned of the rising risk of wildfires amid a protracted heat wave that has dried out the landscape while setting temperature records and putting lives at risk. Forecasters, meanwhile, said Thursday that some relief was due by the weekend.

California's top fire official said Wednesday that so far this year, the state has responded to more than 3,500 wildfires that have scorched nearly 325 square miles — five times the average burned through July 10 in each of the past five years.

“We are not just in a fire season, but we are in a fire year,” Joe Tyler, director of the California Department of Forestry and Fire Protection, said at a news conference. “Our winds and the recent heat wave have exacerbated the issue, consuming thousands of acres. So we need to be extra cautious.”

California crews working in scorching temperatures and single-digit humidity were battling numerous wildfires Thursday, including a stubborn 53-square-mile blaze that prompted evacuation orders for about 200 homes in the mountains of Santa Barbara County northwest of Los Angeles. It was 16% contained.

California’s fires began in earnest in early June, following back-to-back wet winters that pulled the state out of drought but spawned abundant grasses that have since dried out. A June blitz of lightning ignited some of the fires, a risk that may return with thunderstorms in the Sierra Nevada this weekend, forecasters said.

Fire crews in Oregon continued Thursday to fight the Larch Creek Fire, which has grown to 16.6 square miles of grassy areas since Tuesday. Lower temperatures and calming winds were helping their efforts, but the local fire danger level remained extreme. One firefighter was treated for heat-related injuries.

Officials in Oregon and Washington state have imposed burn bans and other restrictions to avoid sparks. Campfires, operating chainsaws and target shooting are prohibited in most areas. Central Oregon limits the use of chainsaws and grass mowing to certain hours, followed by a one-hour fire watch.

In Hawaii, Haleakala National Park on Maui was closed as firefighters battled a blaze on the slopes of the mountain. Visitors in more than 150 vehicles that had gone up Wednesday for the famous sunset views were not able to descend until around 4 a.m. Thursday because the narrow roads were blocked by fire crews.

No homes were immediately threatened, but some residents were told to prepare for possible evacuations. The 40 mph wind speeds were a concern for firefighters, Maui Fire Department spokesperson Chris Stankis said. “The winds are a little stronger than our typical trade winds,” he said.

The blaze is several miles from an area where 26 structures burned during deadly wind-driven wildfires on Maui last August. “But the residents who lost homes are scared,” said Yuki Lei Sugimura, who represents the area on the Maui County Council. “It’s like PTSD.”

More than 63 million people around the U.S. remained under heat alerts Thursday, a significant reduction from earlier this week.

The National Weather Service said the combination of power outages from Hurricane Beryl and heat indices up to 106 degrees Fahrenheit prompted heat advisories across parts of southeast Texas. In Western states, where dozens of locations tied or broke heat records since the weekend, torrid conditions were expected through Friday before some cooling.

Las Vegas on Thursday simmered into a record sixth consecutive day of temperatures at 115 degrees or greater. The temperature hit 115 shortly before 1 p.m. at Harry Reid International Airport, and it could get hotter still before the sun goes down. It extends a newly broken record set Wednesday when Las Vegas reached 118, toppling the old record of four consecutive days set in July 2005, according to the National Weather Service.

Forecasters called it an unprecedented heat wave, even for desert standards.

Kip Kelly, who works and lives in Las Vegas, keeps his car and the office of the nonprofit theater he founded stocked with umbrellas that he can hand out to people who don’t have access to adequate cooling in the summer. The gesture began two summers ago when Kelly saw someone “hugging a wall for a sliver of shade” in downtown, where trees tend to be far and few between. Experts call this the urban heat island effect, where heavily paved areas with sparse vegetation trap more heat than outlying areas.

Meteorologist Morgan Stessman said the Las Vegas area has been under an excessive heat warning on three separate occasions this year, totaling about 12 days of dangerous heat with little relief even after the sun goes down. The city also has broken 18 heat records since June 1, well before the official start of summer, including an all-time high of 120 set on Sunday.

In Henderson, Nev., officers from the Office of Public Response drove around Wednesday offering cold water, bus passes and rides to cooling stations to homeless people and anyone else in need.

In California, officials in the Silicon Valley county of Santa Clara are investigating 19 potential heat-related deaths, including three homeless individuals, the county’s Medical Examiner-Coroner’s Office said in a statement Thursday.

The Oregon state medical examiner reported Thursday four new potentially heat-related deaths, bringing to 14 the total number of deaths since the heat wave began. Two were from Washington County, including the second woman, and the other two were from Jackson and Linn counties.

Heat was also blamed for a motorcyclist’s death last weekend in Death Valley National Park, and the National Park Service is investigating the third death of a Grand Canyon hiker in recent weeks. Arizona authorities are investigating deaths of a 2-year-old and a baby in separate incidents, and in Nebraska, Omaha police say a boy died after being left in an SUV.

The U.S. heat wave came as the global temperature in June was a record warm for the 13th straight month and marked the 12th straight month that the world was 2.7 degrees Fahrenheit warmer than pre-industrial times, the European climate service Copernicus said. Most of this heat, trapped by human-caused climate change, is from long-term warming from greenhouse gases emitted by the burning of coal, oil and natural gas, scientists say.

“Climate change is real,” California Gov. Gavin Newsom said at a news conference Wednesday. “Those extremes are here present every day in the great state of California.”

Newsom said the state was prepared to fight the conflagrations.

Cal Fire uses 1,100 cameras and artificial intelligence to spot fires. The agency also has the largest fire suppression aircraft fleet in the world, according to Newsom. This year, the state will add 24 privately owned planes to its force and will begin using seven ex-military planes provided by the federal government. The state has added 3,000 firefighters since 2018 and is committed to hiring an additional 2,400 in the next five years.

In southern New Mexico, heavy rain produced flash flooding on top of wildfire burn scars for the second day in a row Wednesday, forcing an estimated 1,000 residents to flee their homes in Ruidoso, city spokesperson Kerry Gladden said.

She said emergency responders had conducted more than 30 water rescues but there were no immediate reports of deaths or serious injuries. She said most bridges over rivers and streams were closed, as was U.S. Highway 70 — one of the main arteries into town — while crews removed debris.