Following a chilly rain during part of the weekend, the coolest air since the spring will settle over the Northeast Sunday night into Monday morning.
Temperatures are forecast to dip into the 50s from Boston and New York City to Philadelphia and Washington, D.C. The last time readings were this low was during the first couple of days of June in most cases and in late May in others.
The northern and western suburbs of the Interstate-95 cities will dip well down into the 40s. Cities forecast to drop into the 40s this weekend include Pittsburgh, Buffalo, New York, and Burlington, Vermont.
Some locations from northern Pennsylvania, upstate New York and northwestern New England will dip into the 30s. Provided skies remain clear and winds diminish, there is a risk of scattered frost for a few hours late Sunday night into Monday morning.
In addition to the potential for the first frost in the normally colder locations, light winds and clearing skies overhead will allow perfect conditions for fog to form. The fog may slow the morning commute on Monday over the river valleys, especially in the Appalachians.
The batch of cool air will be reinforced at times next week. However, the air mass will slowly moderate.
High temperatures are forecast to be in the 70s in most major cities during most days next week, with nighttime lows in the 50s.
Temperatures may rebound to warm levels by next weekend for a several-day period before September draws to a close.
Meanwhile, in the South, the warm and humid conditions will slowly slip away through the weekend and into next week. By next week, highs most days will be in the 70s from Atlanta to Charlotte, North Carolina, and Richmond, Virginia.
Even in the Deep South from Louisiana to Florida, highs are forecast to be in the 80s, rather than the 90s, most days next week.
While few records are expected to be broken in the East as the cool air settles in at the middle of the month, the fresh cold air made its mark over the Central states this past week.
Multiple locations in the Central states set record low maximum temperatures. Some of the records have been in place since the 1800s.