Frost Dates for 01267 — Williamstown, Massachusetts

Half of springs at North Adams Harriman Airport, MA see their last 32°F night by May 10; only one in ten is past it by April 27, and one in ten still has one after May 25. Planting tender crops after May 17 leaves a 30% risk of a frost on them, after May 20 20%, and after May 25 10%. The 15 days between the even-odds date and the one-in-ten date is wider than at 83% of the 71 Massachusetts stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 4 in half of years, as early as September 21 one year in ten, and holds off past October 19 one year in ten. A hard freeze of 28°F follows 13 days later, around October 17; in spring the one-in-ten date for 28°F is May 15, 10 days before the 32°F one. The freeze-free season lasts 147 days in a typical year, shorter than at 96% of the 71 Massachusetts stations; it reaches 167 days one year in ten and falls short of 127 one year in ten. On average 149 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 12 days longer, to about May 22, and return around September 25. Severe cold of 16°F or below comes every winter, usually between November 25 and March 24.

July is the warmest month at North Adams Harriman Airport, MA, averaging 81°F by day and 58°F at night; January is the coldest at 32°F and 14°F. A freezing night is all but certain in every month from October to April (a 90% chance or more). From June to August the chance of a 32°F night stays under 10% each month. In spring, May still brings one in 79% of years.

Warmth for growing adds up to 2,291 growing degree days a year (base 50°F), fewer than at 92% of the 71 Massachusetts stations. 31% of them (720) have built up by the end of June, and July adds the most, 598. Precipitation totals 42.3 inches a year, most in August (4.5") and least in February (2.0"); May to September bring 49% of it.

The nearest other station, Pownal 1 NE, VT, 7 miles north of Williamstown and 456 feet higher, has a last frost 3 days earlier (May 7), a first frost 4 days later (October 8), a season 7 days longer.

The first measurable snow (0.1 inch or more) in Williamstown usually arrives around November 9, and the last of the season around April 5. Those are the middle dates across the winters of 1991–2020 at Pownal 1 NE, VT, 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 35 days after the last snow.

ZIP 01267 is 3 miles from North Adams Harriman Airport, MA, which stands at 654 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 3 other ZIP codes share the station; its figures are presented in full for 01247 (North Adams). The 2023 USDA Plant Hardiness Zone Map lists ZIP 01267 in zone 5b, the band where the coldest night of the year averaged -15 to -10°F (-26.1 to -23.3°C) over 1991–2020; a zone describes winter lows, not frost dates.