Frost Dates for 01020 — Chicopee, Massachusetts

Half of springs at Westfield Barnes Municipal Airport, MA see their last 32°F night by May 3; only one in ten is past it by April 20, and one in ten still has one after May 17. Planting tender crops after May 9 leaves a 30% risk of a frost on them, after May 12 20%, and after May 17 10%. The 14 days between the even-odds date and the one-in-ten date is wider than at 51% of the 71 Massachusetts stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 8 in half of years, as early as September 26 one year in ten, and holds off past October 25 one year in ten. A hard freeze of 28°F follows 12 days later, around October 20; in spring the one-in-ten date for 28°F is May 5, 12 days before the 32°F one. The freeze-free season lasts 158 days in a typical year, shorter than at 80% of the 71 Massachusetts stations; it reaches 179 days one year in ten and falls short of 139 one year in ten. On average 144 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 14, and return around September 30. Severe cold of 16°F or below comes every winter, usually between November 29 and March 17.

July is the warmest month at Westfield Barnes Municipal Airport, MA, averaging 85°F by day and 61°F at night; January is the coldest at 35°F and 16°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 60% of years.

Warmth for growing adds up to 2,798 growing degree days a year (base 50°F), more than at 70% of the 71 Massachusetts stations. 32% of them (899) have built up by the end of June, and July adds the most, 710. Precipitation totals 45.3 inches a year, most in October (4.7") and least in February (2.6"); May to September bring 45% of it.

The nearest other station, Westfield 3 SW, MA, 13 miles southwest of Chicopee and 159 feet higher, has a last frost 5 days earlier (April 28), a first frost 9 days later (October 17), a season 13 days longer.

The first measurable snow (0.1 inch or more) in Chicopee usually arrives around November 30, and the last of the season around March 23. Those are the middle dates across the winters of 1991–2020 at Belchertown, MA, 13.5 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 41 days after the last snow.

ZIP 01020 is 8 miles from Westfield Barnes Municipal Airport, MA, which stands at 271 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 22 other ZIP codes share the station; its figures are presented in full for 01085 (Westfield). The 2023 USDA Plant Hardiness Zone Map lists ZIP 01020 in zone 6a, the band where the coldest night of the year averaged -10 to -5°F (-23.3 to -20.6°C) over 1991–2020; a zone describes winter lows, not frost dates.