Frost Dates for 08242 — Rio Grande, New Jersey

Half of springs at Cape May 2 NW, NJ see their last 32°F night by April 1; only one in ten is past it by March 19, and one in ten still has one after April 15. Planting tender crops after April 7 leaves a 30% risk of a frost on them, after April 10 20%, and after April 15 10%. The 14 days between the even-odds date and the one-in-ten date is narrower than at 66% of the 56 New Jersey stations behind this site's ZIP pages.

In fall the first 32°F night comes by November 9 in half of years, as early as October 26 one year in ten, and holds off past November 26 one year in ten. A hard freeze of 28°F follows 14 days later, around November 23; in spring the one-in-ten date for 28°F is March 31, 15 days before the 32°F one. The freeze-free season lasts 222 days in a typical year, longer than at 86% of the 56 New Jersey stations; it reaches 242 days one year in ten and falls short of 201 one year in ten. On average 72 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 16 days longer, to about April 17, and return around October 29. Severe cold of 16°F or below comes in 91% of winters, usually between January 8 and February 7.

July is the warmest month at Cape May 2 NW, NJ, averaging 86°F by day and 68°F at night; January is the coldest at 43°F and 29°F. A freezing night is all but certain in every month from November to March (a 90% chance or more). From May to September the chance of a 32°F night stays under 10% each month. In spring, April still brings one in 53% of years.

Warmth for growing adds up to 3,833 growing degree days a year (base 50°F), more than at 80% of the 56 New Jersey stations. 31% of them (1,202) have built up by the end of June, and July adds the most, 834. Precipitation totals 43.9 inches a year, most in October (4.2") and least in February (3.0"); May to September bring 43% of it.

The nearest other station, Belleplain Stn Forest, NJ, 16 miles north of Rio Grande, has a last frost 23 days later (April 24), a first frost 18 days earlier (October 22), a season 41 days shorter.

The first measurable snow (0.1 inch or more) in Rio Grande usually arrives around December 27, and the last of the season around March 2. Those are the middle dates across the winters of 1991–2020 at Cape May 2 NW, NJ, 5.5 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 08242 is 6 miles from Cape May 2 NW, NJ, which stands at 20 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 4 other ZIP codes share the station; its figures are presented in full for 08210 (Cape May Court House). The 2023 USDA Plant Hardiness Zone Map lists ZIP 08242 in zone 8a, the band where the coldest night of the year averaged 10 to 15°F (-12.2 to -9.4°C) over 1991–2020; a zone describes winter lows, not frost dates.