A severe heatwave spread across the United States on Saturday, with forecasters predicting temperatures reaching triple-digits in the Southwest and Great Plains over the weekend, the Associated Press reported.Meteorologists said the heatwave could spread eastward under a dome of high pressure, trapping the oppressive temperatures for more than a week, according to the report. It is expected to affect as much as two-thirds of the continental US.The heatwave comes after the National Weather Service (NWS), early in July, put nearly 120 million people under an extreme heat warning, the BBC reported. The NWS had further predicted that temperatures would range between 32 degrees Celsius and 40 degrees Celsius with high humidity, adding that the heat could push the maximum temperatures to around 46 degrees Celsius, Euro News reported.Citizens take precautionary measuresTemperatures in North Dakota will exceed 100 degrees Fahrenheit (37 degrees Celsius) until Tuesday. The forecasters have advised people to stay hydrated and find shelters to cool themselves off, as temperatures are likely to be 15 to 26 degrees Fahrenheit — 8 to 14 degrees Celsius — warmer than normal in several areas, even at night, the AP report stated.Many could be seen handing out frozen towels, washcloths, and battery-supported fans alongside water, food, and hygiene supplies at encampments around St. Paul, which will continue until next week.Residents, struggling to walk or cycle to nearby cooling centres, were seen putting the ice packs around their necks and heads, as temperatures in the area are expected to reach 90 degrees Fahrenheit. People fan themselves while waiting in line for the ferris wheel at the Great American State Fair on the National Mall, July 1, 2026, in Washington. (AP Photo)Record temperaturesMore than 90 local temperature records would be tied or broken by Wednesday — two-thirds of those being overnight heat records — according to predictions of the US National Weather Service.Story continues below this adTemperatures will not drop below 80 degrees Fahrenheit — 27 degrees Celsius — at night in Fort Lauderdale, Florida; Miami; Tampa, Florida; Galveston, Texas; and Charleston, South Carolina, the weather agency noted.Record triple-digit highs have also been forecast for the weekend in Nevada, Utah, Colorado, Wyoming, Idaho, Montana, and the Dakotas, AP reported. While the temperatures in Helena, Montana, are expected to reach 95 degrees Fahrenheit (35 degrees Celsius), Nevada was even hotter than normal, with temperatures expected to hit 111 degrees Fahrenheit (48 degrees Celsius).Climate change accelerates heatThe heat dome, one of the reasons behind the prevalent heatwave in the US, forms when high pressure traps hot air while blocking cooling winds and rain.It is one of the strongest to affect the Dakotas in 25 years, Chad Merrill, a senior meteorologist with AccuWeather, told AP.Story continues below this adExplained | Behind ongoing heatwave in the US, a combination of heat dome and climate change Visitors use fans as they wait to enter the Washington Monument. (AP Photo)Meteorologists have also warned that the heat could spike the risk of fire in some parts of the country that are already dry, including the Rockies, the report noted.According to the scientists, climate change from the burning of coal, oil, and natural gas is causing intense and longer-lasting heat waves that cover larger areas of the planet.Moreover, temperatures this year are expected to be affected by El Niño — a warming of the equatorial Pacific that interferes with weather patterns and leads to spikes in temperatures across the globe.By fall in 2026, the El Niño has an 81 per cent chance of becoming “very strong”, according to the US National Oceanic and Atmospheric Administration.