By Ashley R. Williams and Mary Gilbert, CNN

(CNN) — The first significant heat wave of the year is expected to hit a significant portion of the central and southern United States on Father’s Day Sunday with potentially record-breaking high temperatures, four days away from the official start of summer.

The National Weather Service warned people in the South and Midwest who plan to celebrate fathers outdoors on Sunday stay cool amid a high heat risk, with high temperatures reaching the 90s in some areas.

The intense heat wave will not stop there. An extensive and exceptionally strong heat dome will build across the East on Sunday and extend into the Midwest and Great Lakes over the next few days, with heat expected to persist throughout the week.

Heat domes hold the air in place and bake it in abundant sunshine for days, making each day hotter than the last.

The last Sunday of spring will bring scorching heat across the Plains and Midwest, where temperatures will reach the mid to upper 90s, according to the Weather Prediction Center.

People living in the Great Lakes region can expect temperatures in the upper 80s and low 90s.

Iowa and Missouri will be hit by the worst of Sunday’s sweltering conditions, with large parts of both states facing a Level 3 — or high — risk of heat-related impacts.

The National Weather Service Office in St. Louis encouraged residents to take extra precautions Sunday due to the hottest day of the year. “It will feel like 100-105 in the afternoon hours. We are not yet used to this kind of heat,” forecasters wrote on X, formerly Twitter.

Sunday’s lingering heat will be felt in states including Kansas, Illinois, Tennessee, Arkansas and Mississippi, according to the weather service.

A few locations like Atlanta will experience some smaller areas of Level 4 – or extreme – heat, where temperatures could reach 102 degrees by midday on Sunday.

Millions will face heat-related health risks as conditions reach extreme levels this week, according to a scale from the National Weather Service and the Centers for Disease Control and Prevention. Heat is the deadliest form of weather in the US, killing on average more than twice as many people per year as hurricanes and tornadoes combined.

Persistent heat could break records this week

The extreme temperatures and uncomfortable heat will seep into larger cities in the Midwest and Northeast by the start of the work week. On Monday, temperatures in Chicago could reach 99 degrees with a heat index of 105 degrees forecasters at the weather service office in Chicago.

According to the Weather Prediction Center, high temperatures in the Upper Ohio Valley and Great Lakes regions will climb into the mid-90s on Monday, with the potential to tie or break numerous records.

The potential for record-breaking heat will continue through Friday in the Ohio Valley and the Northeast, with some areas reaching heat indices of 105 degrees, the Weather Prediction Center said.

A Level 3 heat risk is expected to affect large parts of states including Wisconsin, Illinois, Indiana and Ohio on Monday, according to the weather service. Meanwhile, much of the southern half of Iowa faces an extreme heat risk on Monday.

Weather service forecasters in Des Moines, Iowa, warned of high temperatures and humidity on Tuesday push into the 90s and heat index values ​​reached almost triple digits.

“Morning lows will be just as impressive as temperatures remain in the mid to upper 70s,” the Weather Prediction Center said.

“The combination of heat, humidity and low nighttime lighting will potentially have widespread, significant heat-related impacts for anyone without adequate hydration or reliable cooling,” the center said.

In Detroit, where daytime temperatures are expected to reach the high 90s, the city’s urban core won’t see much relief after dark. That’s what weather service forecasters say Overnight lows will only dip into the 70s this week.

The sweltering conditions will continue to shift into the eastern and northeastern US on Tuesday.

CNN’s Elisa Raffa contributed to this report.

The CNN Wire
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