Frost Dates for 02535 — Chilmark, Massachusetts

Half of springs at Vineyard Haven Airport, MA see their last 32°F night by May 7; only one in ten is past it by April 22, and one in ten still has one after May 27. Planting tender crops after May 16 leaves a 30% risk of a frost on them, after May 20 20%, and after May 27 10%. The 20 days between the even-odds date and the one-in-ten date is the widest of the 71 Massachusetts stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 9 in half of years, as early as September 23 one year in ten, and holds off past October 31 one year in ten. A hard freeze of 28°F follows 16 days later, around October 25; in spring the one-in-ten date for 28°F is May 13, 14 days before the 32°F one. The freeze-free season lasts 156 days in a typical year, shorter than at 87% of the 71 Massachusetts stations; it reaches 179 days one year in ten and falls short of 132 one year in ten. On average 115 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 14 days longer, to about May 21, and return around September 28. Severe cold of 16°F or below comes every winter, usually between December 5 and March 13.

July is the warmest month at Vineyard Haven Airport, MA, averaging 79°F by day and 61°F at night; January is the coldest at 39°F and 23°F. A freezing night is all but certain in every month from November 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 64% of years.

Warmth for growing adds up to 2,441 growing degree days a year (base 50°F), fewer than at 79% of the 71 Massachusetts stations. 26% of them (638) have built up by the end of June, and July adds the most, 625. Precipitation totals 42.3 inches a year, most in October (4.4") and least in February (2.6"); May to September bring 39% of it.

The nearest other station, Edgartown, MA, 12 miles east of Chilmark, has a last frost 20 days earlier (April 17), a first frost 25 days later (November 3), a season 43 days longer.

The first measurable snow (0.1 inch or more) in Chilmark usually arrives around December 20, and the last of the season around March 18. Those are the middle dates across the winters of 1991–2020 at Edgartown, MA, 12.4 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 50 days after the last snow.

ZIP 02535 is 8 miles from Vineyard Haven Airport, MA, which stands at 68 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 2 other ZIP codes share the station; its figures are presented in full for 02568 (Vineyard Haven). The 2023 USDA Plant Hardiness Zone Map lists ZIP 02535 in zone 7b, the band where the coldest night of the year averaged 5 to 10°F (-15.0 to -12.2°C) over 1991–2020; a zone describes winter lows, not frost dates.