Frost Dates for 02655 — Osterville, Massachusetts

Half of springs at Hyannis, MA see their last 32°F night by April 16; only one in ten is past it by April 5, and one in ten still has one after April 30. Planting tender crops after April 22 leaves a 30% risk of a frost on them, after April 25 20%, and after April 30 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 30 in half of years, as early as October 15 one year in ten, and holds off past November 13 one year in ten. A hard freeze of 28°F follows 12 days later, around November 11; in spring the one-in-ten date for 28°F is April 15, 15 days before the 32°F one. The freeze-free season lasts 195 days in a typical year, longer than at 85% of the 71 Massachusetts stations; it reaches 215 days one year in ten and falls short of 175 one year in ten. On average 101 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 13 days longer, to about April 29, and return around October 19. Severe cold of 16°F or below comes every winter, usually between December 22 and March 3.

July is the warmest month at Hyannis, MA, averaging 78°F by day and 64°F at night; January is the coldest at 39°F and 22°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 10% of years.

Warmth for growing adds up to 2,518 growing degree days a year (base 50°F), fewer than at 70% of the 71 Massachusetts stations. 25% of them (640) have built up by the end of June, and July adds the most, 656. Precipitation totals 45.7 inches a year, most in March (4.8") and least in July (2.8"); May to September bring 36% of it.

The nearest other station, Hyannis Barnstable Municipal Airport, MA, 6 miles northeast of Osterville, has a last frost 6 days later (April 22), a first frost 2 days earlier (October 28), a season 7 days shorter.

The first measurable snow (0.1 inch or more) in Osterville usually arrives around January 2, and the last of the season around March 6. Those are the middle dates across the winters of 1991–2020 at Hyannis, MA, 4.8 miles away: half of years saw snow earlier, half later. Snow fell in 86% of those winters. The last 32°F night of spring typically comes 41 days after the last snow.

ZIP 02655 is 5 miles from Hyannis, MA, which stands at 60 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 02601 (Hyannis). The 2023 USDA Plant Hardiness Zone Map lists ZIP 02655 in zone 7a, the band where the coldest night of the year averaged 0 to 5°F (-17.8 to -15.0°C) over 1991–2020; a zone describes winter lows, not frost dates.