More than 250 million Americans will feel late-summer heat this week before a cold front drops temperatures by around 40 degrees into the weekend.
A sprawling dome of high pressure is pumping warm, humid air north across the Southern Plains, Mid-South, Southeast, Great Plains, Midwest, and Deep South, setting up an October stretch that looks more like late summer than fall.
FOX Weather reports that over 20 states will see above-average temperatures, with the FOX Forecast Center expecting hundreds of daily record highs to be tied or broken through Wednesday.
St. Louis, Chicago, Atlanta, and Charlotte are among the cities on track for their hottest readings of the season so far.
Temperatures across the Southern Plains, Mid-South, and Southeast are forecast to climb into the mid- to upper 90s early in the week.
The Midwest is expected to reach the upper 80s and 90s. In parts of the South, heat index values are expected to top 100 degrees.
That is not a typical fall pattern. It is a broad, persistent warm surge locked in by high pressure, and it is set to touch a huge share of the country before the pattern breaks.
Later in the week, a fall cold front is forecast to sweep through the Central and Eastern United States and shut the heat wave down.
Temperatures are expected to drop by around 40 degrees from the midweek peak into the weekend, returning large areas to more seasonable levels and then some.
Overnight lows are forecast to plunge into the 30s and lower 40s through the weekend across much of the affected region.
Morning frost is expected to return to the Upper Midwest and Central Great Plains as overnight temperatures settle into the 30s and lower 40s.
Farther east, the Northeast, Mid-Atlantic, and Great Lakes are in line for plummeting fall temperatures as cold, dry Arctic air takes hold under a dominant high-pressure system.
Interior valleys across Pennsylvania, New York, and northern New England could drop into the upper 20s and low 30s. Forecasters point to this weekend, and Sunday morning in particular, as a shot at the season’s coldest mornings so far, with millions possibly waking up to frost.
The deep chill is not framed as a permanent shift. Forecasters expect warm temperatures to return at some point next week after the cold shot moves through.
In practical terms, the same broad stretch of the country that spends early in the week chasing records and sweating through heat-index readings above 100 may finish the stretch checking for frost on windshields and fields.
That swing, from mid- and upper-90s heat to overnight readings in the 20s and 30s, is the core of the forecast. No watches, warnings, or damage tallies were detailed in the outlook; the story is the pattern itself, the scale of the population in its path, and the speed of the change.
When the calendar says fall and the thermometer still reads summer, then flips toward freeze in a matter of days, the only reliable move is to watch the sky and plan for both extremes, not the slogan on the season.
