Western US heat dome shatters records, sparks wildfire warnings

A severe heat wave has engulfed the western United States, bringing near-record temperatures to several states and raising alarm over wildfire risks. Forecasters on Saturday (August 1, 2026) warned residents to remain indoors as a high-pressure system, commonly called a heat dome, parked itself over the region from Arizona to Montana.

The National Weather Service reported exceptional highs expected across the affected areas. Las Vegas braced for a high of 115°F (46°C), the hottest reading there this year. Phoenix was predicted to touch 116°F (47°C), while El Centro, California, was poised for a record 118°F (48°C). Even parts of Montana were not spared, with Great Falls anticipating a record-breaking 104°F (40°C).

Weather service meteorologist Morgan Stessman noted that Las Vegas would experience temperatures 10 degrees above normal, with dangerous conditions persisting into Sunday (August 2), when the mercury was expected to hit 114°F. Overnight lows in the upper 80s to low 90s offered no relief, a factor that amplifies health risks. “There's just no relief overnight,” Mr. Stessman said, urging people to stay hydrated and indoors.

In Phoenix, the Justa Center, a cooling facility primarily for seniors but open to all in the afternoon, reported a daily influx of around 200 people. Operations director Rudy Soliz said the biggest challenge is keeping up with the demand for water and electrolytes. “Anybody can come in, get a meal, sign up, get checked in through the cooling centre, sit down, relax, watch a little TV, you know, catch themselves before they move on to another cooling centre or their destination,” he explained.

The situation in several cities is approaching historic marks. Las Vegas's August record stands at 116°F, while its all-time high is 120°F, set in July 2024, which was also the hottest summer on record. In Montana, an extreme heat warning covered the entire eastern half of the state, though meteorologist Jeff Kitsmiller said much of the state would cool into the 70s by Sunday. Great Falls was on track to surpass its previous record of 101°F, and Helena was expected to match or exceed its record of 102°F.

Mr. Kitsmiller noted that this heat wave is not as severe as the one in mid-July, when Billings hit an all-time high of 111°F. “That was a rare heat wave,” he said. “This one fits for this time of year.” Still, communities were taking precautions. The Montana Rescue Mission in Billings opened its doors early on Saturday, offering shelter and meals to dozens of people seeking relief from temperatures that could reach 106°F. Public swimming pools and splash pads in Great Falls were crowded, with recreation centre worker Katy Houseman observing, “They're definitely hitting the pools and doing the splash pads outside and then trying to hide inside where there's air conditioning. It's super, super hot today.”

The heat is also heightening wildfire risks across the West, as dry conditions compound the danger. Mr. Kitsmiller expressed concerns for Montana, where fires are already burning and high winds are forecast for the weekend. Most of the state was under a red flag warning. In Nevada, the heat dome has sapped relative humidity, further escalating fire threats. Emergency officials across the region are urging residents to exercise caution and follow safety guidelines.