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Port Jefferson, NY Weather & Growing Conditions

Local forecast, frost dates, hardiness zone and planting guidance for Port Jefferson, a village in Suffolk County, New York.

Overnight
66°F
Partly Cloudy
Partly cloudy, with a low around 66. North wind around 3 mph.

7-day forecast for Port Jefferson

WhenTempForecastWindPrecip
Overnight 66°F Partly Cloudy 3 mph N 0%
Tuesday 82°F Mostly Sunny 2 to 6 mph NE 0%
Tuesday Night 66°F Mostly Cloudy 5 mph E 6%
Wednesday 82°F Partly Sunny 2 to 6 mph SE 9%
Wednesday Night 71°F Mostly Cloudy then Slight Chance Rain Showers 6 mph S 18%
Thursday 87°F Mostly Sunny 5 to 12 mph SW 11%
Thursday Night 73°F Slight Chance Showers And Thunderstorms then Mostly Clear 6 to 12 mph SW 19%
Friday 88°F Mostly Sunny then Slight Chance Showers And Thunderstorms 6 to 9 mph SW 20%
Friday Night 73°F Slight Chance Showers And Thunderstorms then Chance Showers And Thunderstorms 5 to 9 mph SW 30%
Saturday 87°F Mostly Sunny then Slight Chance Showers And Thunderstorms 5 to 8 mph SW 23%
Saturday Night 72°F Slight Chance Showers And Thunderstorms then Chance Showers And Thunderstorms 5 to 8 mph SW 25%
Sunday 87°F Mostly Sunny 5 to 8 mph SW 13%
Sunday Night 73°F Mostly Clear 5 to 8 mph SW 10%
Monday 88°F Sunny 5 to 9 mph W 8%

Forecast source: National Weather Service (api.weather.gov) for Port Jefferson (40.942, -73.053). Updated through the day.

Growing snapshot for Port Jefferson

Last spring frost
Apr 15
First fall frost
Nov 10
Growing season
208 days
Hardiness zone
7b

More local growing data for Port Jefferson: nearby ZIP 11777 weather · frost dates · planting calendar · New York frost dates

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Climate data from the nearest NOAA station, Setauket Strong, Ny (2 mi from Port Jefferson). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.