Severe heat grips western US, raising health and wildfire risks

Blistering heat blanketed the western United States on Saturday, with temperatures hovering near record highs, increasing the risks of heat-related illness and wildfire.

The US National Weather Service (NWS) has issued extreme heat warnings for parts of California, Arizona, Nevada and Utah, with temperatures in some southwestern deserts forecast to reach 49 degrees Celsius.

According to weekend forecasts, temperatures in Sacramento, California's capital, could exceed 39.4 degrees Celsius. Palm Springs in inland California is expected to reach 47.2 degrees Celsius, while Death Valley, a desert valley in eastern California known for its extreme heat, could soar to 50.6 degrees Celsius.

Salt Lake City, Utah, is forecast to reach 40.6 degrees Celsius, while Las Vegas, Nevada, could hit 46.1 degrees Celsius. In Arizona, the capital Phoenix is expected to reach 43 to 47 degrees Celsius through Monday, with highs of 44 to 49 degrees Celsius forecast for Yuma, a city near the Mexican border.

The NWS warned that the dangerous heat is expected to persist across much of the West over the coming days.

Daniel Swain, a climate scientist at the University of California, Los Angeles, said the prolonged heat is being driven by a strong high-pressure ridge, commonly known as a heat dome.

According to NASA's Earth Observatory, such systems trap hot air near the surface while suppressing cloud formation and precipitation, allowing extreme temperatures to persist.

The prolonged heat is already taking a toll on public health. The latest data from Maricopa County, Arizona, showed 40 confirmed heat-related deaths so far this year, compared with 17 during the same period in 2025. In nearby Clark County, Nevada, officials reported 41 confirmed heat-related deaths as of Wednesday, with another five cases under investigation.

Authorities have warned of a heightened risk of heat-related illness and urged residents to stay indoors whenever possible, remain hydrated, and take precautions against heat exposure. Some cities have also opened cooling centers and other facilities to provide relief from the extreme heat.

"Heat causes more deaths in the US annually than floods, storms and lightning combined," Muntu Davis, Los Angeles County's health officer, said in a county news release earlier this week. He noted that older adults, young children, outdoor workers, and people with chronic medical conditions are especially vulnerable to heat-related illness.

Moreover, meteorologists warned that the ongoing heat wave, combined with weeks of exceptionally dry conditions, could further increase the risk of wildfires. Several areas have issued red flag warnings, indicating an extremely high fire risk.

According to the National Interagency Fire Center, 84 large fires are actively burning across the United States as of Saturday, the vast majority in the West. More than 26,000 firefighters and support personnel have been deployed to battle the blazes.

In Washington state, Governor Bob Ferguson declared a statewide wildfire emergency on Saturday as drought conditions, unusually high temperatures and high winds exacerbated the record-setting wildfires. A fast-moving wildfire swept across northwest Spokane in eastern Washington state on Saturday, prompting the evacuation of thousands of people.

Looking ahead, the NWS Climate Prediction Center said above-normal temperatures are likely to prevail across most of the United States through mid-August.

The World Meteorological Organization warned on Friday that El Nino, a powerful climate pattern shaping global weather, is expected to dominate global climate patterns in the August-October 2026 season, increasing the likelihood of above-normal temperatures across much of the world and driving significant shifts in rainfall patterns.