Summer's Over: Temperatures Drop Up to 20 Degrees as Fall Chill Arrives

Last week's summerlike warmth has been replaced by the coldest air of the season thus far for a large swath of the Great Lakes and into the interior portions of the Northeast. How cold is it going to get, and when will the chill arrive? We have everything that you need to know right here.

Summer Warmth Replaced by Winter Chill in Northeastern U.S.

The higher terrains of the Great Lakes and the Northeast are under the threat of the first frost or freeze of the season as temperatures plummet to the lowest levels since last spring. Millions of Americans will be left shivering early this week as a mass of cold air dips down from Canada and into some parts of the northern U.S.

The chill will come as quite the shock after last Friday's toasty temperatures. The mercury soared into the mid to upper 80s up and down much of the Interstate 95 corridor to end the work week.

A cold front pushed into the region late Friday, sending temperatures on a downward trajectory that has held. Temperatures were hovering about 10 to 20 degrees lower than Friday's high marks by Sunday afternoon. The clear skies and weakening winds will naturally raise the risk of frost or freeze conditions early Tuesday morning.

Water temperatures across the Great Lakes are still relatively warm. The warmth radiating off these large bodies of water will help to mitigate the risk of an overnight frost along the Great Lakes shorelines. The larger cities in the region will also see temperatures bottom out above frost threat level due to the urban island heat effect.

When and Where to Expect Frost or Freeze Conditions

This means the highest chance of a frost or freeze this week will be in areas further inland and in rural locations. The higher elevations of the region will be most likely to experience temperatures capable of creating a widespread frost or freeze.

The chance of a freeze or frost will inch farther to the east by Tuesday and early Wednesday, encompassing parts of the Appalachians and the interior Northeast. As is typical for this time of the year, the highest risk of a freeze that kills vegetation will be in the northern mountains of Pennsylvania and to the north into New York's Adirondacks and Vermont's Green Mountains.

For instance, places such as Stowe, Vermont, are forecast to dip down into the low to mid 30s after the sun goes down on Tuesday. You will find a similar situation in nearby Montpelier, Vermont. While not quite at the freezing level, it will be a cold start to the day Wednesday in Albany, New York. The capital city is forecast to dive into the upper 30s.

While it may seem early for the first frost or freeze of the season, the historical average for this event in the interior Northeast ranges between October 1 and 15. This makes this week's event right on schedule.

Meteorologists are warning those in the impact zone to bring sensitive vegetation indoors or cover it up. This could be the end of the growing season if proper precautions are not taken.

On a positive note, the zone of high pressure responsible for the cold overnight temperatures will also usher in dry conditions, an abundance of bright sunshine, and comfortable afternoon readings. This is a great time to take a drive through the northern reaches of New England to check out the peak fall foliage. The chilly overnight temperatures will accelerate the changing of the leaves, bringing an end to the season shortly in this part of the country.

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