Frost Dates for 02360 — Plymouth, Massachusetts

Half of springs at Plymouth Municipal Airport, MA see their last 32°F night by April 30; only one in ten is past it by April 19, and one in ten still has one after May 12. Planting tender crops after May 4 leaves a 30% risk of a frost on them, after May 8 20%, and after May 12 10%. The 12 days between the even-odds date and the one-in-ten date is narrower than at 83% of the 71 Massachusetts stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 16 in half of years, as early as October 3 one year in ten, and holds off past November 1 one year in ten. A hard freeze of 28°F follows 11 days later, around October 27; in spring the one-in-ten date for 28°F is May 2, 10 days before the 32°F one. The freeze-free season lasts 170 days in a typical year, longer than at 55% of the 71 Massachusetts stations; it reaches 188 days one year in ten and falls short of 153 one year in ten. On average 127 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 10 days longer, to about May 10, and return around October 5. Severe cold of 16°F or below comes every winter, usually between December 5 and March 12.

July is the warmest month at Plymouth Municipal Airport, MA, averaging 82°F by day and 62°F at night; January is the coldest at 38°F and 20°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 47% of years.

Warmth for growing adds up to 2,641 growing degree days a year (base 50°F), fewer than at 52% of the 71 Massachusetts stations. 28% of them (752) have built up by the end of June, and July adds the most, 679. Precipitation totals 48.1 inches a year, most in March (5.0") and least in February (3.0"); May to September bring 37% of it.

The nearest other station, Plymouth-Kingston, MA, 7 miles northwest of Plymouth, has a last frost 15 days earlier (April 15), a first frost 16 days later (November 1), a season 28 days longer.

The first measurable snow (0.1 inch or more) in Plymouth usually arrives around December 10, and the last of the season around March 19. Those are the middle dates across the winters of 1991–2020 at Plymouth-Kingston, MA, 7.2 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 42 days after the last snow.

ZIP 02360 is 6 miles from Plymouth Municipal Airport, MA, which stands at 149 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 2 other ZIP codes share the station. The 2023 USDA Plant Hardiness Zone Map lists ZIP 02360 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.