WASHINGTON — A widespread heat wave is expected to bring triple-digit temperatures across much of the United States this weekend and into next week, with forecasters warning that prolonged extreme heat could affect nearly two-thirds of the continental U.S.
The National Weather Service said temperatures in many areas will run 15 to 25 degrees Fahrenheit (8 to 14 degrees Celsius) above normal, with unusually warm overnight lows limiting relief and increasing health risks.
Meteorologists said a strong high-pressure system, known as a heat dome, will trap hot air over large parts of the country for at least a week. More than 90 daily temperature records are forecast to be tied or broken through Wednesday, with most involving record-high nighttime temperatures.
Triple-digit highs are expected across portions of the Southwest, Great Plains and Northern Rockies, including Nevada, Utah, Colorado, Wyoming, Idaho, Montana and the Dakotas. Some areas of North Dakota are forecast to exceed 100 degrees Fahrenheit through Tuesday.
Forecasters urged residents to stay hydrated, avoid prolonged outdoor activity during peak heat, check on vulnerable individuals and seek air-conditioned spaces when possible.
Meteorologists also warned that hot, dry conditions could increase wildfire risk in parts of the Rocky Mountain region.
Scientists said climate change has contributed to more frequent and intense heat waves, while the recently developed El Niño weather pattern is expected to further increase global temperatures later this year.
