Frost Dates for 02370 — Rockland, Massachusetts

Half of springs at Hingham, MA see their last 32°F night by April 25; only one in ten is past it by April 13, and one in ten still has one after May 8. Planting tender crops after April 30 leaves a 30% risk of a frost on them, after May 3 20%, and after May 8 10%. The 13 days between the even-odds date and the one-in-ten date is narrower than at 51% of the 71 Massachusetts stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 22 in half of years, as early as October 6 one year in ten, and holds off past November 5 one year in ten. A hard freeze of 28°F follows 11 days later, around November 2; in spring the one-in-ten date for 28°F is April 24, 14 days before the 32°F one. The freeze-free season lasts 177 days in a typical year, longer than at 63% of the 71 Massachusetts stations; it reaches 197 days one year in ten and falls short of 158 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 11 days longer, to about May 6, and return around October 9. Severe cold of 16°F or below comes every winter, usually between December 12 and March 8.

July is the warmest month at Hingham, MA, averaging 83°F by day and 63°F at night; January is the coldest at 38°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 28% of years.

Warmth for growing adds up to 2,921 growing degree days a year (base 50°F), more than at 85% of the 71 Massachusetts stations. 30% of them (882) have built up by the end of June, and July adds the most, 719. Precipitation totals 52.3 inches a year, most in March (5.4") and least in July (3.6"); May to September bring 37% of it.

The nearest other station, Brockton, MA, 8 miles southwest of Rockland, has a last frost 3 days earlier (April 22), a first frost 3 days earlier (October 19), a season 1 day longer.

The first measurable snow (0.1 inch or more) in Rockland usually arrives around December 4, and the last of the season around March 31. Those are the middle dates across the winters of 1991–2020 at Hingham, MA, 6.7 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 25 days after the last snow.

ZIP 02370 is 7 miles from Hingham, MA, which stands at 35 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 12 other ZIP codes share the station; its figures are presented in full for 02169 (Quincy). The 2023 USDA Plant Hardiness Zone Map lists ZIP 02370 in zone 6b, the band where the coldest night of the year averaged -5 to 0°F (-20.6 to -17.8°C) over 1991–2020; a zone describes winter lows, not frost dates.