A Frost Advisory covers Aroostook County and northern Piscataquis County overnight into Wednesday, with temperatures forecast to fall as low as 37 degrees across the top of Maine.
Aroostook County and Northern Piscataquis: Frost Advisory Details
The NWS Caribou office has the advisory in effect from 2 AM to 9 AM EDT Wednesday for northeastern Aroostook, northwestern Aroostook and northern Piscataquis counties.
Forecasters expect temperatures as low as 37 degrees, cold enough to bring frost formation to low-lying areas and open fields. Fort Kent, Caribou, Presque Isle, Van Buren, Madawaska, Allagash, Frenchville, Mars Hill and Ashland are all included, along with more remote spots like Baxter State Park, Mount Katahdin, Chamberlain Lake and Churchill Dam.
A Pattern Building Over the Past Two Days
This isn’t a surprise development. NWS Caribou has been flagging the cooldown since a cold front crossed the region over the weekend, bringing partly to mostly sunny, dry weather behind it and setting the stage for clear, calm nights that let temperatures drop quickly after sunset.
By Monday, forecasters were already highlighting the potential for frost in northern areas overnight, mainly across the north and in the usual low-lying cold pockets. That risk carried into Tuesday night, prompting Wednesday’s advisory, before the pattern flips again: rain moves in Wednesday night into Thursday, along with a return of breezier conditions.
Hazy Skies Add to an Unusual Week
Adding to the atmosphere this week, wildfire smoke drifting south from Canada has periodically hazed the skies over northern Maine, a reminder that early September in this part of the state can bring a mix of lingering summer smoke, sharp overnight cooldowns and the first real taste of fall all in the same week.
What It Means for Gardens and Farms
Frost can harm sensitive outdoor vegetation, and plants left uncovered overnight may not survive. Aroostook County’s farms, known for potatoes and other cold-hardy crops, are generally past the most frost-vulnerable stage of the season, but home gardens with tomatoes, peppers, squash and flowers are still very much at risk.
How to Protect Tender Plants
Take steps now to protect tender plants from the cold. Covering garden beds with sheets, burlap or frost cloth before nightfall can trap enough ground heat to keep temperatures a few degrees above the surrounding air. Potted plants can simply be moved indoors or into a garage overnight.
Harvest any remaining frost-sensitive produce ahead of the cold if possible, since even a light frost can end the growing season for the most vulnerable plants.
What Comes Next
Relief from the frost risk arrives quickly. Rain is forecast to move into the region Wednesday night and continue into Thursday, bringing warmer, more humid air behind it and effectively ending this particular cold snap, even as breezier conditions return along with the wet weather.
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