Where the Freeze Risk Will be the Greatest as the Temperatures Plunge in the East

An advancing cold front coming down from the Rockies will push into the Upper Midwest and the Northeast in the coming days, sending residents reaching for their blankets and covering sensitive plants. Here is a closer look at when the chill will arrive and how low the mercury will settle.

Intensely Colder Temperatures Headed to the Northeast and Beyond

A dramatic cooldown is on the way for the Upper Midwest, the Great Lakes, and the Northeast. The arrival of a potent cold front will quickly erase the summerlike warmth that has distinguished the last several days across much of the eastern U.S. Temperatures will plunge from readings most commonly seen in June and July to levels typically seen in March. The colder air will settle in beginning this weekend and lasting through early next week. Although the chill in the air will not linger, it will be cold enough for long enough to cause damage to sensitive vegetation.

The forecast is calling for daily highs to slide about 20 to 40 degrees in a period of just 24 to 48 hours. This trajectory will mean highs that have been reaching the 70s, 80s, and low 90s will swap places with top readings in the 30s, 40s, and 50s. A small zone in northern New York and the northwestern corner of New England could see the influx of cold air mix with lingering rain to briefly change the precipitation over to snow on Sunday. The chances of snow will be the greatest in the Green Mountains and the Adirondacks.

While most areas will dodge the chance of wintry precipitation, the sharp drop in temperatures will fuel the development of widespread frost and freeze conditions. The threat of these impacts will be the highest in areas away from the lakeshores of the Great Lakes and into the interior Northeast. The early morning hours on Monday and Tuesday will see the greatest chance of freezing temperatures.

Monday's threat of a frost or freeze will stretch from Minnesota to the east into northern Pennsylvania, upstate New York, and up into the northern reaches of New England. The silver lining for this region is that most of the sensitive plants have not finished the blooming process. This means that these buds will still be protected as the mercury drops.

The primary danger zone will be overnight Monday and into Tuesday when the widespread freezing conditions migrate farther south. A zone of building high pressure, clear skies, and light winds will work together to deliver the perfect storm for a freeze to take root across interior New England, upstate New York, portions of Pennsylvania, and down into West Virginia. The coldest areas will see temperatures slip into the 20s overnight, cold enough to trigger a hard freeze.

The largest metro areas in the region, including Chicago, Philadelphia, Boston, New York City, and Washington, D.C., will likely be protected from vegetation damage by the urban heat island effect. This will not be the case for some of the outlying areas, particularly in zones with sandy soil along the mid-Atlantic coastline.