Frost Dates for 01034 — Granville, Massachusetts

Half of springs at Westfield 3 SW, MA see their last 32°F night by April 28; only one in ten is past it by April 15, and one in ten still has one after May 11. Planting tender crops after May 3 leaves a 30% risk of a frost on them, after May 6 20%, and after May 11 10%. The 13 days between the even-odds date and the one-in-ten date is narrower than at 51% of the 71 Massachusetts stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 17 in half of years, as early as October 2 one year in ten, and holds off past October 31 one year in ten. A hard freeze of 28°F follows 13 days later, around October 30; in spring the one-in-ten date for 28°F is April 30, 11 days before the 32°F one. The freeze-free season lasts 171 days in a typical year, longer than at 56% of the 71 Massachusetts stations; it reaches 192 days one year in ten and falls short of 152 one year in ten. On average 143 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 9, and return around October 5. Severe cold of 16°F or below comes every winter, usually between December 1 and March 17.

July is the warmest month at Westfield 3 SW, MA, averaging 84°F by day and 61°F at night; January is the coldest at 33°F and 16°F. A freezing night is all but certain in every month from November to April (a 90% chance or more). From June to September the chance of a 32°F night stays under 10% each month. In spring, May still brings one in 40% of years.

Warmth for growing adds up to 2,704 growing degree days a year (base 50°F), more than at 55% of the 71 Massachusetts stations. 32% of them (855) have built up by the end of June, and July adds the most, 690. Precipitation totals 52.5 inches a year, most in October (5.2") and least in February (3.6"); May to September bring 42% of it.

The nearest other station, Barkhamsted, CT, 11 miles south of Granville and 280 feet higher, has a last frost 2 days later (April 30), the same first-frost date, a season 3 days shorter.

The first measurable snow (0.1 inch or more) in Granville usually arrives around December 7, and the last of the season around March 20. Those are the middle dates across the winters of 1991–2020 at Barkhamsted, CT, 11.5 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 39 days after the last snow.

ZIP 01034 is 7 miles from Westfield 3 SW, MA, which stands at 430 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 01077 (Southwick). The 2023 USDA Plant Hardiness Zone Map lists ZIP 01034 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.