- Cities like Memphis and St. Louis were under “excessive heat advisories.”
- Such readings are considered dangerous, and the Weather Service said heat-related illnesses are possible.
- Out west, temperatures could drop as low as 40 degrees in the southwestern US early this week.
More than 100 million Americans were under some kind of heat warning or advisory on Monday as a withering and potentially record-breaking heat wave slammed into the central and eastern US.
The heat moved east after scorching parts of the west late last week and over the weekend. Phoenix, Las Vegas and Denver were among the cities that saw record temperatures.
Southerly winds were expected to push warm, moist air into the eastern two-thirds of the nation through Wednesday, and temperatures could exceed 10 to 30 degrees above normal, forecasters warned.
“Limit strenuous outdoor activities and sun exposure!” warned the National Weather Service in Chicago.
Chicago could reach 100 degrees
Temperatures in Chicago could reach 100 degrees Tuesday, along with “oppressive humidity,” the weather service warned.
If Chicago reaches the century mark, it would be the first time in nearly 10 years that the Windy City has seen such a high temperature, AccuWeather said.
Tens of thousands of Chicago residents suffered power outages Monday night following severe thunderstorms and winds up to 60 miles per hour. As of 10 p.m. ET, there were 882 active blackouts in the metro area, affecting nearly 75,000 customers, according to Chicago’s only electricity provider, ComEd.
Memphis, Tennessee and St. Louis could set record highs and were under “excessive heat warnings.” Heat index values, how the weather feels when humidity is taken into account, could approach 110 degrees this week.
Such conditions are dangerous, and the weather service said heat-related illnesses are possible.
“This is serious heat, so don’t underestimate it,” the weather service in Memphis said. “Stay inside if possible. Keep an eye on neighbors, especially the elderly, and check the backseat for children and pets.”
HEAT WAVE: Historic heat wave sweeps much of US
Heat record for many cities
AccuWeather Meteorologist Dan Pydynowski said, “Even cities as far east as Charlotte and Raleigh, North Carolina, will be flirting with record temperatures and triple-digit readings this week.”
Minneapolis and Tulsa, Oklahoma, were under excessive heat advisories.
About 100 cities could post record highs through Wednesday, the weather service predicted.
Excessive heat causes more deaths in the US than other weather-related disasters, including hurricanes, floods, and tornadoes combined.
The ‘heat dome’ is to blame
The heat results from a large area of high pressure, known as a “heat dome,” Pydynowski said. High-pressure atmospheric conditions are combining with La Niña influences, creating vast areas of sweltering heat that are trapped under a “dome,” according to the National Oceanic and Atmospheric Administration.
The heat dome will spread across the central and southeastern US in the coming days, Pydynowski said.
Scientists say more frequent and intense heat waves are likely due to climate change.
Cooling, even snow in the West
In the west, after a weekend of record heat, a strong cold front was expected to bring cooler temperatures across much of California and the Great Basin on Monday.
Temperatures could drop as low as 40 degrees across the Southwest early this week as a new weather pattern drives off intense heat, AccuWeather said.
Daytime temperatures across the Northwest as far north as the Rockies are expected to be 10 to 20 degrees below normal, the weather service said.
Winter storm watches and advisories were in effect for the mountains of northwestern Montana, including the Glacier National Park area, where several inches of wet snow was expected for elevations above 5,000 feet, according to the weather service.
Contributing: The Associated Press