Frost Dates for 08243 — Sea Isle City, New Jersey

Half of springs at Belleplain Stn Forest, NJ see their last 32°F night by April 24; only one in ten is past it by April 5, and one in ten still has one after May 18. Planting tender crops after May 3 leaves a 30% risk of a frost on them, after May 10 20%, and after May 18 10%. The 24 days between the even-odds date and the one-in-ten date is the widest of the 56 New Jersey stations behind this site's ZIP pages, so a fixed calendar date is a gamble here.

In fall the first 32°F night comes by October 22 in half of years, as early as October 8 one year in ten, and holds off past November 3 one year in ten. A hard freeze of 28°F follows 13 days later, around November 4; in spring the one-in-ten date for 28°F is May 3, 15 days before the 32°F one. The freeze-free season lasts 181 days in a typical year, shorter than at 71% of the 56 New Jersey stations; it reaches 204 days one year in ten and falls short of 153 one year in ten. On average 118 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 May 7, and return around October 13. Severe cold of 16°F or below comes every winter, usually between December 19 and March 1.

July is the warmest month at Belleplain Stn Forest, NJ, averaging 88°F by day and 66°F at night; January is the coldest at 46°F and 25°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 37% of years.

Warmth for growing adds up to 3,772 growing degree days a year (base 50°F), more than at 79% of the 56 New Jersey stations. 34% of them (1,265) have built up by the end of June, and July adds the most, 831.

The nearest other station, Margate, NJ, 17 miles northeast of Sea Isle City, has a last frost 29 days earlier (March 26), a first frost 31 days later (November 22), a season 62 days longer.

The first measurable snow (0.1 inch or more) in Sea Isle City usually arrives around December 16, and the last of the season around March 21. Those are the middle dates across the winters of 1991–2020 at Estell Manor, NJ, 17.8 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 34 days after the last snow.

ZIP 08243 is 11 miles from Belleplain Stn Forest, NJ, which stands at 30 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 08270 (Woodbine). The 2023 USDA Plant Hardiness Zone Map lists ZIP 08243 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.