A significant heat dome is currently impacting approximately 70 million people across 15 U.S. states, with temperatures forecast to reach triple digits and pose a potentially lethal threat within minutes under extreme conditions.
The National Weather Service (NWS) has issued widespread extreme heat warnings for states including California, Arizona, Nevada, Utah, and Colorado. These warnings are expected to persist through at least Sunday, with some regions anticipating record-breaking heat to last until late next week.
Major metropolitan areas such as Las Vegas and Phoenix are projected to experience temperatures exceeding 115 degrees Fahrenheit over the weekend. In parts of Southern California, temperatures could climb as high as 120 degrees Fahrenheit.
The NWS has cautioned that the severity of dehydration and heat stroke risks in affected areas is so high that individuals should avoid alcohol consumption, high-protein meals, and prolonged periods in vehicles. "Car interiors will reach lethal temperatures in a matter of minutes," the agency stated.
This expansive heat dome is attributed to a large high-pressure system situated over the western United States. This system traps warm, humid air, preventing it from dissipating and leading to soaring temperatures that are 10 to 20 degrees above average for late July and early August. The affected states include parts of Oregon, Idaho, Montana, Wyoming, New Mexico, Texas, Minnesota, Nebraska, and the Dakotas.
In addition to the extreme heat, the heat dome is forecast to interact with strengthening winds in the Northwest, significantly increasing the risk of wildfires across several states.