The chilly air swinging through the northeastern United States will not relinquish its grip into at least the middle of May.
For most, the cool pattern will result in temperatures averaging 5 to 15 degrees Fahrenheit below-normal levels. For some, the pattern will be more reminiscent of winter as wet snowflakes can fall and a frost or freeze can occur.
Clouds and a slight breeze will protect much of the region from a frost. Locations, especially in the higher terrain, where skies clear out and winds diminish overnight will be at greatest risk of a damaging frost or freeze.
“Mornings through Tuesday will be cold across the eastern Ohio Valley, West Virginia, western Virginia and the northern mid-Atlantic,” AccuWeather Lead Long-Range Meteorologist Paul Pastelok said.
“There is a chance for some frost in the western areas of this region,” he added.
Those who have already done some planting and gardening should take necessary precautions, such as covering plants or bringing them indoors, to prevent damage to sensitive vegetation.
The threat for a frost will diminish towards the coast as overnight lows will dip into the 40s from Boston to Washington, D.C. Middle to upper 30s are likely in the north and west suburbs.
“Sweatshirts, jeans and heavier jackets may be needed when heading out for any evening activities or sporting events,” AccuWeather Meteorologist Brett Rathbun said. “Many will also turn on heat in their homes.”
Afternoon highs will stay unseasonably cool in the mid-Atlantic despite times of the strong May sun. Even as the chill eases by midweek, highs will remain several degrees below normal.
The brunt of the chill will linger across upstate New York and New England, where clouds will be more stubborn to erode and wet snowflakes can mix with rain showers through Tuesday. Any accumulations will be very light and remain confined to the highest terrain.
Those hoping to break out the shorts and t-shirts for warm weather activities once again will likely have to wait until the second half of the month, when near- to slightly above-normal temperatures are expected to return.
While the chill may seem out of the ordinary after the extremely warm April across the region, bouts of cool air and late-season frosts are not usual during May.
The average date of the last frost is around the middle of May along the coast, and beyond the middle of the month farther inland across the higher terrain.