Frost Dates for 11951 — Mastic Beach, New York

Half of springs at Shirley Brookhaven Airport, NY see their last 32°F night by April 18; only one in ten is past it by April 4, and one in ten still has one after May 1. Planting tender crops after April 23 leaves a 30% risk of a frost on them, after April 26 20%, and after May 1 10%. The 13 days between the even-odds date and the one-in-ten date is narrower than at 83% of the 173 New York stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 28 in half of years, as early as October 13 one year in ten, and holds off past November 11 one year in ten. A hard freeze of 28°F follows 12 days later, around November 9; in spring the one-in-ten date for 28°F is April 17, 14 days before the 32°F one. The freeze-free season lasts 193 days in a typical year, longer than at 87% of the 173 New York stations; it reaches 211 days one year in ten and falls short of 172 one year in ten. On average 104 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 12 days longer, to about April 30, and return around October 17. Severe cold of 16°F or below comes every winter, usually between December 20 and March 2.

July is the warmest month at Shirley Brookhaven Airport, NY, averaging 83°F by day and 66°F at night; January is the coldest at 39°F and 24°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 12% of years.

Warmth for growing adds up to 3,060 growing degree days a year (base 50°F), more than at 86% of the 173 New York stations. 29% of them (892) have built up by the end of June, and July adds the most, 747. Precipitation totals 44.3 inches a year, most in March (4.6") and least in January (3.0"); May to September bring 39% of it.

The nearest other station, Upton Coop - Nwsfo New York, NY, 7 miles north of Mastic Beach, has a last frost 3 days later (April 21), a first frost 4 days earlier (October 24), a season 9 days shorter.

The first measurable snow (0.1 inch or more) in Mastic Beach usually arrives around December 12, and the last of the season around March 19. Those are the middle dates across the winters of 1991–2020 at Upton Coop - Nwsfo New York, NY, 7.1 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 11951 is 4 miles from Shirley Brookhaven Airport, NY, which stands at 82 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 9 other ZIP codes share the station; its figures are presented in full for 11763 (Medford). The 2023 USDA Plant Hardiness Zone Map lists ZIP 11951 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.