Iselin, NJ Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Iselin, a community in Middlesex County, New Jersey.
Today
84°F
Mostly Sunny
Mostly sunny, with a high near 84. Northeast wind 0 to 5 mph.
7-day forecast for Iselin
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 84°F | Mostly Sunny | 0 to 5 mph NE | 0% |
| Tonight | 66°F | Mostly Cloudy | 0 to 5 mph E | 1% |
| Wednesday | 83°F | Mostly Cloudy then Chance Showers And Thunderstorms | 0 to 5 mph E | 45% |
| Wednesday Night | 72°F | Slight Chance Showers And Thunderstorms then Chance Showers And Thunderstorms | 0 to 5 mph S | 29% |
| Thursday | 90°F | Slight Chance Rain Showers then Chance Showers And Thunderstorms | 0 to 10 mph SW | 38% |
| Thursday Night | 74°F | Chance Showers And Thunderstorms | 5 mph SW | 38% |
| Friday | 90°F | Mostly Sunny then Chance Showers And Thunderstorms | 5 mph SW | 43% |
| Friday Night | 73°F | Chance Showers And Thunderstorms | 5 mph W | 43% |
| Saturday | 88°F | Partly Sunny then Chance Showers And Thunderstorms | 5 mph W | 37% |
| Saturday Night | 72°F | Chance Showers And Thunderstorms | 0 to 5 mph W | 37% |
| Sunday | 89°F | Mostly Sunny | 5 mph W | 13% |
| Sunday Night | 73°F | Mostly Clear | 5 mph W | 13% |
| Monday | 91°F | Mostly Sunny | 5 to 10 mph W | 8% |
| Monday Night | 72°F | Partly Cloudy | 5 to 10 mph W | 13% |
Forecast source: National Weather Service (api.weather.gov) for Iselin (40.570, -74.316). Updated through the day.
Growing snapshot for Iselin
Last spring frost
Apr 11
First fall frost
Oct 28
Growing season
198 days
Hardiness zone
7a
More local growing data for Iselin: nearby ZIP 08830 weather · frost dates · planting calendar · New Jersey frost dates
Nearby towns & communities
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Climate data from the nearest NOAA station, Plainfield, Nj (5.1 mi from Iselin). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.