Extreme, record-breaking heat will bake a large portion of the southern tier of the USA early this week.
After a sweltering weekend, heat advisories and excessive heat warnings remained in place Monday across the southern USA all the way from Southern California to the Florida Panhandle, and there was the potential for more record high temperatures and very dangerous heat indices, the National Weather Service said.
Temperatures could come within a few degrees of record highs set as far back as the Dust Bowl era of the 1930s, AccuWeather said.
"Excessively hot temperatures and high humidity may cause heat illnesses to occur," the weather service in New Orleans warned.
Dozens of record highs were set across the Southwest on Sunday.
Sunday, Phoenix had its hottest day since July 25, 2018, soaring to a record 116 degrees, weather.com said. The city is threatening its record-long streak of daily low temperatures that did not drop out of the 90s.
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Palm Springs, California, hit a record high of 121, the weather service said.
California's notorious hot spot, Death Valley, soared to 128 degrees Sunday, and its overnight low was a searing 100 degrees, according to the weather service.
In the South, temperatures near 100 degrees and high humidity will make it feel like it is 105 to 115 in some areas this week, ABC News reported.
"When combined with higher humidity levels, it could feel worse to some people when compared to that of the Southwest, especially in heavily urbanized areas where there is little breeze during the afternoon and early evening hours," AccuWeather meteorologist Alex Sosnowski said.
This dangerous heat is the result of a large ridge of high pressure that stretches from the Desert Southwest to the Deep South; the center is anchored over the southern Rockies, according to WeatherBug.
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Southerly winds associated with this system will pump very warm air northward, resulting in the mercury climbing to levels 5 to 20 degrees above normal for this time of year, WeatherBug said.
According to weather.com, the dome of high pressure responsible for the Southwest heat wave will expand and stretch east across much of the rest of the country late this week.
Also Monday, severe thunderstorms with all hazards, including tornadoes, hail, damaging winds and heavy rain, are expected during the afternoon and evening from the Upper Midwest to the central High Plains, the weather service warned.
This article originally appeared on USA TODAY: Heat wave: Dangerous, record-breaking heat scorches southern USA