At least 40 million people were under extreme heat warnings across central and southern parts of the United States on Sunday as high temperatures and severe humidity gripped large swaths of the country for a second straight day.
Heat indexes well above 100 degrees Fahrenheit stretched from Minnesota down to Mississippi, extending west into southern California and Nevada. Parts of the Southwest were expected to see highs of 120 degrees Fahrenheit, according to the National Weather Service.
Meteorologists said the sweltering weather was the result of another heat dome—a phenomenon in which atmospheric conditions trap heat, accentuating and prolonging already high temperatures.
“It’s extraordinarily hot,” said Pete Miller, an outreach manager for the homeless services network Threshold CoC, which was passing out water bottles to residents in Omaha, Nebraska, on Sunday….