More than 100 million Americans to swelter in triple digit heat as new ‘heat dome’ arrives

Temperatures are expected to hit over 100 degrees Fahrenheit during the day in multiple areas including parts of Nebraska, Missouri, Texas and Louisiana

More than 100 million Americans are set to swelter in triple-digit heat in the coming days after an area of high pressure moves across the Midwest and South, resulting in the arrival of a new “heat dome.”

Temperatures are expected to hit over 100 degrees Fahrenheit during the day in multiple areas including parts of Nebraska, Missouri, Texas and Louisiana. Overnight some areas may not dip below 80 degrees.

It comes almost exactly a month after similar severe heatwaves scorched parts of the East Coast, with several major cities including New York and Boston climbing to triple-digit temperatures.

John F Kennedy International Airport recorded 100 degrees Fahrenheit (38C) at midday – the first time since 2013 – according to the National Weather Service, which described the conditions caused by the heat dome as “extremely dangerous.”

Temperatures are expected to hit over 100 degrees during the day in multiple areas across the American Midwest and South. Overnight some areas may not dip below 80 degrees (Reuters)

The new heat dome comes almost exactly a month after similar severe heatwaves scorched parts of the East Coast, with several major cities including New York and Boston climbing to triple-digit temperatures (AP)

A heat dome is created when a high pressure area stays over the same area for days or potentially weeks, trapping very warm air underneath it. Because hot air expands, it creates a “dome” that bulges out.

According to the National Weather Service, such conditions are set to hit the South in the coming week.

“Dangerous, prolonged heat is expected across portions of the Central and Southeast U.S. through the end of July,” the NWS said. “Widespread Major to locally Extreme HeatRisk is expected, especially over the Mid-Mississippi, Lower Ohio Valleys, and the Mid South.”

Forecaster AccuWeather noted that Dallas, Texas, is at risk of hitting triple figure temperatures on any given day during the next two or three weeks. Over 100 million Americans will feel heat over 100 degrees, the forecaster said.

Millions of Americans were placed under heat warnings in late June after days of record-breaking temperatures. Multiple major U.S. cities experienced triple digit heat (Charly Triballeau/AFP via Getty Images)

"Kansas City, Missouri, has not hit 100 degrees since August 25 2023, but is positioned to do so on multiple days during the upcoming heat dome," AccuWeather Senior Meteorologist Chad Merrill said.

"The zone from central Texas into the Ozarks in Arkansas and Missouri still has wet soil from recent rain," Merrill said, adding such conditions would contribute to the “extreme” humidity.

Such sweltering temperatures will hinder manual labor jobs including construction and agriculture. The high temperatures are also expected to impact the start of athletic training camps for the upcoming start of the school year.

During June’s Northeast heat dome nearly 40 U.S. cities broke record high temperatures, including Philadelphia, Baltimore and Raleigh, North Carolina (AFP via Getty Images)

While this occurs, those in the Northeast will enjoy a brief respite from the extreme heat, thanks to “a large southward dip in the jet stream,” AccuWeather reports.

This pattern will result in frequent fronts that bring extended bouts of cool and less humid air, and although there will be brief surges of hot and humid weather, previously unbearable conditions are due to dissipate.

During June’s Northeast heat dome nearly 40 U.S. cities broke record high temperatures, including Philadelphia, Baltimore and Raleigh, North Carolina, which hit temperatures of 99 degrees (37C), 104 degrees (40C) and 100 degrees, respectively.