A dramatic cooldown swept across the Mid-Atlantic, bringing record-breaking temperatures and even a touch of late-summer frost to parts of the region.

Thursday morning saw temperatures plunge into the 40s and 50s across much of the eastern U.S., setting daily record lows in several locations. In Charlottesville, Va., the thermometer dipped to 50 degrees, marking the city's coldest August temperature in over a decade.

Dulles, Va., just 23 miles west of Washington, D.C., hit a brisk 49 degrees, breaking the previous daily record low of 51 set back in 1969. While Washington, D.C., didn't get quite as chilly as its surroundings—thanks to the Potomac River and the urban heat island effect, which helps keep temperatures more stable overnight—it was still a noticeable dip for late August.

In the higher elevations of the Appalachians, temperatures dropped even further, bottoming out in the 30s. Frost likely formed in the early morning hours, a rare occurrence for this time of year and more reminiscent of early to mid-fall than late summer.

As the day progresses, temperatures are expected to bounce back sharply, with highs reaching the upper 70s and lower 80s by the afternoon.