By Daily Mail (U.S.) | Created at 2026-08-17 15:16:16 | Updated at 2026-08-17 16:14:22
1 hour ago
A week-long heat dome is set to send temperatures into potentially life-threatening territory as a dozen states and 100 million people brace for temperatures hotter than the Sahara Desert.
Extreme heat warnings have been issued by the National Weather Service (NWS) in Arkansas, Louisiana, Mississippi, Alabama, Tennessee, Florida, Georgia and the Carolinas which are expected to last through Monday night.
A massive high-pressure system over the Gulf Coast has locked in extreme heat and humidity since last week, with the heat index today expected to reach 115 degrees Fahrenheit throughout the Southeast and Gulf states.
The heat index is the 'feels like' temperature, which is hotter when the air is more humid. On a 90-degree day, high humidity can make the 'feels like' temperature reach 105°F.
However, forecasters with AccuWeather have predicted highs in several major cities - including Little Rock, Arkansas, Charleston, South Carolina and Jacksonville, Florida - nearing 100°F, potentially pushing the heat index into a lethal zone for many residents.
Weather officials have urged residents smothered by the heat dome to stay indoors and in air conditioning, if possible, especially during the afternoon and evening hours on Monday as prolonged outdoor exposure could quickly lead to dehydration and illness.
NWS officials added that the high heat and humidity trapped over the Southeast will also make sitting in a locked car lethal in a matter of minutes, especially for children and pets.
The heat dome, which acts like a steam cooker, has made the entire region roughly 20°F hotter than conditions throughout the Sahara Desert, which is only forecasted to be in the 80s and 90s on Monday.
Extreme heat warnings have been issued throughout the Southeast, urging 100 million people to avoid outdoor activity on August 17 (Stock Image)
Twelve states are expected to see the heat index approach 115 degrees Fahrenheit on August 17
AccuWeather Senior Meteorologist Brett Anderson said in a statement: 'This is the type of heat that can quickly lead to heat exhaustion or worse if proper precautions are not taken.'
NWS has also issued heat advisories in Texas, Oklahoma and Missouri, where the heat index is also expected to reach the triple-digits.
The nearly three million people living in Mississippi are in the heart of the heat dome, with almost the entire state under an extreme heat warning that will last until Tuesday or Wednesday.
NWS wrote in a statement: 'There is an elevated to significant threat for dangerous heat to continue today as heat index values approach 115 and actual air temperatures reach the 100 to 104 degree range.'
'Heat stroke [is] increasingly likely with prolonged outdoor activity.'
Heat stroke is a far more deadly condition compared to heat exhaustion and can develop within 15 minutes in extremely hot conditions.
The first symptoms are often a throbbing headache, confusion, slurred speech, nausea, dizziness, and a fever above 103°F.
Sufferers may also develop red, dry, or damp skin, a rapid pulse, and lose consciousness. It turns fatal when the body's organs begin to fail.
This is a breaking story. More details to follow.
A heat dome is a high-pressure system trapping high temperatures and humidity over a large area
AccuWeather warned that Americans will see little relief even after the sun sets, as the nighttime temperatures are forecasted to stay around 85°F, particularly in urban areas.
'Take extra precautions when outside. Wear lightweight and loose fitting clothing. Try to limit strenuous activities to early morning or evening. Take action when you see symptoms of heat exhaustion and heat stroke,' NWS officials in Mississippi recommended.
Dr Omer Awan of the University of Maryland School of Medicine previously told the Daily Mail that the humidity, the amount of water vapor in the air, can be the most dangerous component of this heat wave in the South.
'The more humid it is, the less likely we are to sweat, and then that can make us more prone to heat-related illnesses as well,' Dr Awan explained.
'All these things can happen not in hours, but in minutes if you're exposed to extreme heat outside.'
