South River, NJ Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for South River, a borough in Middlesex County, New Jersey.
Tonight
59°F
Mostly Cloudy
Mostly cloudy, with a low around 59. Southeast wind 0 to 5 mph.
7-day forecast for South River
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 59°F | Mostly Cloudy | 0 to 5 mph SE | 5% |
| Sunday | 75°F | Showers And Thunderstorms | 5 mph SE | 77% |
| Sunday Night | 58°F | Showers And Thunderstorms Likely | 5 mph W | 70% |
| Monday | 69°F | Chance Rain Showers | 5 to 10 mph NE | 29% |
| Monday Night | 54°F | Chance Rain Showers | 5 to 10 mph NE | 29% |
| Tuesday | 66°F | Chance Rain Showers | 10 mph NE | 33% |
| Tuesday Night | 52°F | Chance Rain Showers then Mostly Cloudy | 10 mph NE | 33% |
| Wednesday | 65°F | Slight Chance Rain Showers | 10 to 15 mph NE | 20% |
| Wednesday Night | 52°F | Slight Chance Rain Showers | 10 to 15 mph NE | 22% |
| Thursday | 65°F | Chance Rain Showers | 10 to 15 mph NE | 30% |
| Thursday Night | 51°F | Chance Rain Showers | 10 to 15 mph NE | 36% |
| Friday | 66°F | Chance Rain Showers | 10 to 15 mph N | 37% |
| Friday Night | 52°F | Chance Rain Showers | 10 mph N | 37% |
| Saturday | 70°F | Chance Rain Showers | 10 mph N | 30% |
Forecast source: National Weather Service (api.weather.gov) for South River (40.446, -74.378). Updated through the day.
Growing snapshot for South River
Last spring frost
Apr 15
First fall frost
Oct 26
Growing season
193 days
Hardiness zone
7a
More local growing data for South River: nearby ZIP 08882 weather · frost dates · planting calendar · New Jersey frost dates
Nearby towns & communities
Avenel
Brownville
Carteret
Clearbrook
Colonia
Concordia
Cranbury
Dayton
Deans
East Franklin
Encore at Monroe
Fords
Forsgate
Heathcote
Helmetta
Highland Park
Hopelawn
Iselin
Jamesburg
Keasbey
Kendall Park
Madison Park
Matawan
Menlo Park Terrace
Metuchen
Middlesex
Milltown
Monmouth Junction
New Brunswick
Old Bridge
Climate data from the nearest NOAA station, New Brunswick 3 Se, Nj (3 mi from South River). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 20, 2026.