Frost Dates for 05663 — Northfield, Vermont

Half of springs at Northfield, VT see their last 32°F night by May 18; only one in ten is past it by May 2, and one in ten still has one after May 30. Planting tender crops after May 23 leaves a 30% risk of a frost on them, after May 26 20%, and after May 30 10%. The 12 days between the even-odds date and the one-in-ten date is narrower than at 85% of the 41 Vermont stations behind this site's ZIP pages.

In fall the first 32°F night comes by September 28 in half of years, as early as September 13 one year in ten, and holds off past October 10 one year in ten. A hard freeze of 28°F follows 9 days later, around October 7; in spring the one-in-ten date for 28°F is May 20, 10 days before the 32°F one. The freeze-free season lasts 133 days in a typical year, shorter than at 83% of the 41 Vermont stations; it reaches 153 days one year in ten and falls short of 113 one year in ten. On average 182 nights a year drop to 32°F or below. Nights of 36°F, when frost can still settle on leaves in low, open spots, continue 11 days longer, to about May 29, and return around September 17. Severe cold of 16°F or below comes every winter, usually between November 16 and April 2.

July is the warmest month at Northfield, VT, averaging 81°F by day and 55°F at night; January is the coldest at 29°F and 6°F. A freezing night is all but certain in every month from October to May (a 90% chance or more). From June to August the chance of a 32°F night stays under 10% each month.

Warmth for growing adds up to 2,026 growing degree days a year (base 50°F), fewer than at 61% of the 41 Vermont stations. 31% of them (622) have built up by the end of June, and July adds the most, 556. Precipitation totals 44.8 inches a year, most in July (5.0") and least in February (2.7"); May to September bring 46% of it.

The nearest other station, Barre Montpelier Airport, VT, 6 miles northeast of Northfield and 456 feet higher, has a last frost 2 days earlier (May 16), a first frost 1 day later (September 29), a season 3 days longer.

The first measurable snow (0.1 inch or more) in Northfield usually arrives around November 14, and the last of the season around April 8. Those are the middle dates across the winters of 1991–2020 at Northfield, VT, 1.7 miles away: half of years saw snow earlier, half later. Every one of those winters saw snow. The last 32°F night of spring typically comes 40 days after the last snow.

ZIP 05663 is 2 miles from Northfield, VT, which stands at 670 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 05663 in zone 5a, the band where the coldest night of the year averaged -20 to -15°F (-28.9 to -26.1°C) over 1991–2020; a zone describes winter lows, not frost dates.