Greenly Garden

Frost dates and when to plant in New Jersey

United States

In New Jersey the last spring frost comes between 29 March (Atlantic City) and 6 April (Trenton) — the median of 2016–2025 in 2 cities. The first autumn frost comes between 12 November (Trenton) and 22 November (Atlantic City). The frost-free season lasts 220–238 days. Tomato: plant out into open ground 24 April – 2 August, earliest in Atlantic City, latest in Atlantic City.

Frost dates by city in New Jersey

CityLast spring frostFirst autumn frostFrost-free daysClimate zoneTomato: window
Atlantic City29 March22 November238210–269 frost-free days24 April – 2 August
Trenton6 April12 November220210–269 frost-free days3 May – 23 July

Median of 2016–2025 for the 25 km grid cell of the city: the last day at or below 0 °C in spring and the first in autumn (ERA5 reanalysis via Open-Meteo). In a cold year a frost can come a week or two later — Greenly warns 48 hours ahead.

When to plant in New Jersey: windows by crop

The earliest start and the latest end among the cities here, each with its city; every city’s own window is on its page. Each window starts on the Greenly calendar date and ends on the last day that still leaves the crop’s days to harvest (from its card) before the average first autumn frost, plus six weeks of picking for crops harvested over weeks (tomatoes, peppers, aubergines, cucumbers, courgettes, pumpkins, watermelons, beans) — our rule; earlier in the window is safer.

CropPlanting out or sowing
Tomato24 April (Atlantic City) – 2 August (Atlantic City)
Cucumber5 May (Atlantic City) – 7 September (Atlantic City)
Bell Pepper, Eggplant5 May (Atlantic City) – 2 August (Atlantic City)
Zucchini5 May (Atlantic City) – 5 September (Atlantic City)
Pumpkin5 May (Atlantic City) – 28 July (Atlantic City)
Watermelon5 May (Atlantic City) – 13 August (Atlantic City)
Peas8 March (Atlantic City) – 9 September (Atlantic City)
Garlic, Tulip, Daffodil, Crocus, HyacinthAutumn planting: 13 October (Trenton) – end of December (Trenton)

Weather by month in New Jersey

Across the 2 cities the warmest month is July (average days 28.8 … 31 °C) and the coldest January (average nights -2.7 … -0.8 °C). Every city averages below 0 °C at night in January.

MonthDay, °CNight, °CRain, mm
January5.2 … 6.3 °C-2.7 … -0.8 °C92
February7.8 … 8.4 °C-1.6 … 0.9 °C94
March11.3 … 11.8 °C1.4 … 3.4 °C112
April16.1 … 17.2 °C6.3 … 7.9 °C99
May20.1 … 22.3 °C11.7 … 13 °C130
June25.8 … 27.9 °C17 … 18.6 °C85
July28.8 … 31 °C20.8 … 22.5 °C121
August27.6 … 29.3 °C19.7 … 21.5 °C105
September24.8 … 25.8 °C16.4 … 18.7 °C110
October19.9 °C10.6 … 13.1 °C104
November12.8 … 13.8 °C3.8 … 6.2 °C77
December7.2 … 8.6 °C-0.7 … 1.7 °C108

Day and night: the lowest … highest monthly average among the cities; rain: the middle city (ERA5 via Open-Meteo).

What to plant month by month: the Northeast and Midwest

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