US heat dome pushes temperatures near record highs, raises wildfire risk across West

A scorching heat wave swept across the western United States on Saturday, inching close to record temperatures, heightening wildfire dangers and prompting officials to advise people to stay indoors and well-hydrated. A ridge of high pressure, known as a heat dome, trapped hot air over a swath of states from Arizona to Montana. The oppressive heat caused Las Vegas to hit its hottest temperature of the year at 115°F (46.1°C), just one degree shy of its daily record.

Phoenix headed for 116°F (46.7°C), while El Centro, California, braced for a staggering 118°F (47.8°C), potentially shattering a record. Great Falls, Montana, was on track to reach 104°F (40°C), possibly setting a new state record. Overnight temperatures remained perilously high in parts of Nevada, hovering in the upper 80s to low 90s°F, offering scant respite.

Local authorities warned residents to remain indoors, hydrate, and avoid extended outdoor exposure. Cooling centers across the region reported surging demand, with the Phoenix Justa Center anticipating around 200 visitors on Saturday alone. Billings, Montana, saw the Montana Rescue Mission open early to shelter locals from the extreme temperatures, while Great Falls' public swimming pools and splash pads braced for heavy crowds.

Meteorologists warned that the blend of extreme heat, dry vegetation, and gusty winds was raising wildfire risks throughout the western U.S. Montana remained under a Red Flag Warning, while the US Forest Service cautioned of an elevated wildfire threat across vast swathes of Southern California through Sunday. Nevada's low humidity further fueled fire danger as the heat dome dried out foliage.

Washington Governor Bob Ferguson declared a state of emergency after intense heat and gusty winds fueled multiple wildfires across the state, prompting a ban on most outdoor and agricultural burning through the end of September. The National Weather Service issued a rare "particularly dangerous situation" Red Flag Alert for eastern Washington, where over 312 square miles are ablaze in 12 major wildfires.

A Red Flag Warning also loomed over eastern Oregon, where firefighters battled several large blazes, including the massive Rowe Creek Complex Fire, which had expanded to nearly 490 square miles and was 57% contained.