Frost Dates for 02554 — Nantucket, Massachusetts

Half of springs at Nantucket Mem Airport, MA see their last 32°F night by April 13; only one in ten is past it by April 2, and one in ten still has one after April 27. Planting tender crops after April 19 leaves a 30% risk of a frost on them, after April 22 20%, and after April 27 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 November 8 in half of years, as early as October 25 one year in ten, and holds off past November 23 one year in ten. A hard freeze of 28°F follows 15 days later, around November 23; in spring the one-in-ten date for 28°F is April 12, 15 days before the 32°F one. The freeze-free season lasts 208 days in a typical year, longer than at 96% of the 71 Massachusetts stations; it reaches 228 days one year in ten and falls short of 190 one year in ten. On average 86 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 15 days longer, to about April 28, and return around October 26. Severe cold of 16°F or below comes in 99% of winters, usually between January 1 and February 22.

August is the warmest month at Nantucket Mem Airport, MA, averaging 76°F by day and 62°F at night; January is the coldest at 40°F and 27°F. A freezing night is all but certain in every month from November to April (a 90% chance or more). From May to September the chance of a 32°F night stays under 10% each month.

Warmth for growing adds up to 2,344 growing degree days a year (base 50°F), fewer than at 87% of the 71 Massachusetts stations. 22% of them (521) have built up by the end of June, and August adds the most, 591. Precipitation totals 40.8 inches a year, most in October (4.4") and least in July (2.7"); May to September bring 38% of it.

The nearest other station, Edgartown, MA, 23 miles west of Nantucket, has a last frost 4 days later (April 17), a first frost 5 days earlier (November 3), a season 9 days shorter.

The first measurable snow (0.1 inch or more) in Nantucket 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, 23.4 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 26 days after the last snow.

ZIP 02554 is 2 miles from Nantucket Mem Airport, MA, which stands at 45 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 02554 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.