Frost Dates for 02539 — Edgartown, Massachusetts

Half of springs at Edgartown, MA see their last 32°F night by April 17; only one in ten is past it by April 4, and one in ten still has one after May 3. Planting tender crops after April 22 leaves a 30% risk of a frost on them, after April 27 20%, and after May 3 10%. The 16 days between the even-odds date and the one-in-ten date is wider than at 87% of the 71 Massachusetts stations behind this site's ZIP pages.

In fall the first 32°F night comes by November 3 in half of years, as early as October 20 one year in ten, and holds off past November 18 one year in ten. A hard freeze of 28°F follows 13 days later, around November 16; in spring the one-in-ten date for 28°F is April 17, 16 days before the 32°F one. The freeze-free season lasts 199 days in a typical year, longer than at 89% of the 71 Massachusetts stations; it reaches 219 days one year in ten and falls short of 178 one year in ten. On average 95 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 1, and return around October 22. Severe cold of 16°F or below comes every winter, usually between December 27 and February 25.

July is the warmest month at Edgartown, MA, averaging 80°F by day and 64°F at night; January is the coldest at 40°F and 26°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 13% of years.

Warmth for growing adds up to 2,867 growing degree days a year (base 50°F), more than at 75% of the 71 Massachusetts stations. 26% of them (735) have built up by the end of June, and July adds the most, 691. Precipitation totals 47.6 inches a year, most in March (4.8") and least in July (2.6"); May to September bring 36% of it.

The nearest other station, Vineyard Haven Airport, MA, 5 miles west of Edgartown, has a last frost 20 days later (May 7), a first frost 25 days earlier (October 9), a season 43 days shorter.

The first measurable snow (0.1 inch or more) in Edgartown 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, 0.5 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 30 days after the last snow.

ZIP 02539 is under a mile from Edgartown, MA, which stands at 30 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 02539 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.