Record fall heat wave to bake the Central and Eastern US before a plunge to cold temperatures this weekend

Summer isn't done with the Central and Eastern U.S. just yet.

Millions of people across the Great Plains, Midwest, Deep South and Southeast are in for another round of unseasonable October heat, with temperatures soaring well above average through much of the week.

A sprawling dome of high pressure is pumping warm, humid air north, sending temperatures into the upper 80s and 90s across the Midwest, while the Southern Plains, Mid-South and Southeast climb into the mid- to upper 90s.

Add in the humidity, and it'll feel even hotter. Heat index values are expected to top 100 degrees in parts of the South, making it feel more like the middle of summer than mid-October.

The taste of summer won't last forever, though. A fall cold front is expected to sweep through later this week, knocking temperatures back to more seasonable levels across much of the Central and Eastern U.S.

The FOX Forecast Center expects hundreds of daily record-high temperatures to be tied or broken through Wednesday.

Popular cities such as St. Louis, Missouri, Chicago, Atlanta, and Charlotte, North Carolina, will experience their hottest temperatures so far this season. 

The warming trend will last only until Wednesday as the heat wave fades and a powerful cold front shifts into the Southern U.S. and Southeast toward the end of the work week and through the weekend.

FALL ALLERGIES OR A COLD? HERE’S HOW TO TELL WHAT’S MAKING YOU MISERABLE

The cold front will dramatically decrease temperatures by around 40 degrees when compared to early this week.

Overnight temperatures will plunge into the 30s and lower 40s through the weekend, bringing back morning frost to the Upper Midwest and Central Great Plains.

The Northeast, Mid-Atlantic, and Great Lakes regions will join the trend of plummeting fall temperatures as a dominant high-pressure system locks in cold, dry Arctic air, setting the stage for the season's coldest mornings this weekend.

Sunday morning is expected to be the coldest of the season so far, with millions of Americans possibly experiencing frost.

Interior valleys across Pennsylvania, New York, and northern New England could drop into the upper 20s and low 30s.

WINTER MAKES AN EARLY APPEARANCE AS MOUNT WASHINGTON RECORDS FIRST MEASURABLE SNOW

This welcome trend of frigid temperatures won’t last long, as forecasters expect warm temperatures to return at some point next week.