severe storm threat Thursday
Severe storms for the East Coast as heat remains for the South and central US
02:23 - Source: CNN
CNN  — 

Scorching heat compounded by suffocating humidity is expected to persist through the end of the month in many parts of the US, where millions will likely endure temperatures in the triple digits.

More than 98 million Americans from the West to New England were under either heat warnings or advisories as of Friday morning.

“Temperatures well above normal for this time of year will envelop the northeast over the next few days, peaking on Sunday — when several high temperature records are forecast to be broken.,” the National Weather Service (NWS) tweeted Friday.

On Friday, highs will soar into the 100s in parts of the Southwest, Central Plains and Mississippi River Valley, the NWS’ Weather Prediction Center said. Temperatures also will hit the mid-90s Friday in parts of the Ohio Valley, Mid-Atlantic and Northeast.

But repressive humidity will push the heat index – what the air feels like – even higher in some of these areas Friday and through the weekend, including possible heat index values of 105-110 degrees Friday afternoon in St. Louis and Kansas City, and similar numbers in the Northeast in two days, forecasters warned.

Dallas recorded its first heat-related death of the year, a 66-year-old woman who had underlying health conditions, the County Health and Human Services agency said Thursday.

In Arizona, officials in Maricopa County, reported at least 29 people died from heat-related issues since March – the majority of whom were outdoors. It compares with 16 reported deaths during the same period in 2021, the county’s public health department said. Dozens of other deaths are under investigation in the county for heat-related causes.

The dangerous temperatures have pushed state and local leaders to issue heat emergencies and offer resources to vulnerable residents. They are imploring residents to stay hydrated and limit time outdoors as much as possible.

In Philadelphia, officials extended a heat health emergency through Sunday – meaning resources including cooling centers, home visits by special teams and enhanced daytime outreach to people experiencing homelessness will remain available through the weekend. The forecast high for Sunday is 101 degrees, which would set a daily record and be the hottest temperature there since 2012.

And in Washington, DC, the mayor also announced a heat emergency effective through Monday morning as temperatures are expected to be 95 degrees or higher. Shelters and cooling centers have also opened to serve those who need them, the mayor said.

The extreme heat in the US has also been mirrored in the deadly condition in Europe, where records have been shattered and the European Forest Fire Information System put 19 European countries on “extreme danger” alerts for wildfires.

Grim weekend ahead

About 85% of the US population – or 273 million people – could see high temperatures above 90 degrees over the next week. And about 55 million people could see high temperatures at or above 100 degrees over the next seven days.

Heat index for Friday

By Thursday morning, 60 daily high temperature records had been tied or broken across the US this week, the Weather Prediction Center wrote.

More than 30 weather stations could record near- or record-high temperatures by Sunday, the agency tweeted Friday.

Heat index values – the temperature it feels like when heat is combined with humidity – could top 100 degrees in a number of states through this weekend, particularly in the Midwest, the Southeast and on the East Coast.

Saturday's heat index forecast

On Saturday, “sizzling temperatures” will take hold of the Middle Mississippi Valley and Central Plains with high temperatures forecast to surpass 100 degrees, the weather prediction center said.

On Sunday, the heat index could climb above 105 in parts of the Northeast and Mid-Atlantic on Sunday, the prediction center said.

Daytime temperatures could top 100 degrees across much of the Southwest over the weekend, with some areas exceeding 110 degrees, according to the center.

The south-central region can expect to see high temperatures in the triple digits every day between Sunday and Thursday, the prediction center noted.

“There is some good news in the medium range (after the weekend) as an approaching cold front brings a brief injection of cooler temps to the Midwest and Northeast, but the core of the intense heat shifts to the South Central US and Pacific Northwest early next week,” the prediction center wrote.

 An aerial view of people gathered near a homeless encampment Thursday afternoon in Phoenix, Arizona.

Hiker in South Dakota dies of possible dehydration and exposure

One hiker has died and another was flown to a hospital Wednesday after hiking on an unmarked trail featured in a social media challenge and running out of water at Badlands National Park in South Dakota, according to a release from the Pennington County Sheriff’s Office.

A 22-year-old from St. Louis “collapsed and died from suspected dehydration and exposure,” the Sheriff’s Office said.

The hiker’s 21-year-old companion from Missouri was flown by Life Flight air ambulance to a hospital where he was being monitored for exposure and dehydration due to the hot weather and lack of water, according to the release.

“National parks can be dangerous places,” Brenda K. Todd, acting superintendent of Badlands National Park, told CNN, reminding visitors to be prepared and stay hydrated as the 244,000-acre (381-square-mile) park is experiencing “very high temperatures.”

Highs in the area this week have been in the upper 90s, according to the National Weather Service. Typical July highs are 92 degrees.

The heat has also caused organizers of some outdoor events across the country to postpone. One such event is the Boston Triathlon, which was to hold sprint and Olympic distance contests. The races have been postponed from Sunday to August 21.

High temperatures also threaten livestock

As the high temperatures continue to oppress much of the country, officials are also faced with protecting farmers and their livestock.

In Missouri, the governor declared a drought emergency in 53 of the state’s more than 100 counties to allow farmers to use water from state parks. Officials are also considering use the parks to grow hay to help feed the farmers’ animals.

The situation in Texas is so dire ranchers are running out of water – forcing them to sell their cattle at a rate not seen in more than a decade, according to David Anderson, a livestock economist at Texas A&M University.

The dry, hot conditions are essentially causing grass to die off, severely thinning the pastures where cattle graze, which leaves many ranchers no choice but to send cattle they can’t feed to slaughter.

“A lot of ranchers rely on ponds and tanks that capture rainfall,” Anderson said. “I’ve heard a lot of stories about ranchers running out of water.”

CNN’s Andy Rose, Judson Jones, Paradise Afshar, Dakin Andone, Amir Vera and Amanda Musa contributed to this report.