National Oceanic and Atmospheric Administration National Weather Service United States Department of Commerce
Current conditions at

Islip, Long Island Mac Arthur Airport (KISP)

Lat: 40.79°NLon: 73.1°WElev: 98ft.

Mostly Cloudy

68°F

20°C

Humidity 90%
Wind Speed SW 7 mph
Barometer 30.02 in (1016.5 mb)
Dewpoint 65°F (18°C)
Visibility 10.00 mi
Last update 23 Sep 6:56 am EDT
Extended Forecast for

Port Jefferson Station NY

  • Today

    Today: A slight chance of showers between 2pm and 5pm, then a slight chance of showers and thunderstorms after 5pm. Mostly sunny, with a high near 79. Southwest wind 6 to 10 mph. Chance of precipitation is 20%.

    High: 79 °F

    Mostly Sunny
    then Slight
    Chance
    T-storms

  • Tonight

    Tonight: A chance of showers and thunderstorms. Mostly cloudy, with a low around 65. South wind 6 to 8 mph. Chance of precipitation is 50%.

    Low: 65 °F

    Chance
    Showers

  • Wednesday

    Wednesday: A chance of showers, with thunderstorms also possible after 2pm. Mostly cloudy, with a high near 76. Northwest wind 5 to 7 mph becoming east in the afternoon. Chance of precipitation is 40%.

    High: 76 °F

    Chance
    Showers

  • Wednesday Night

    Wednesday Night: A chance of showers and thunderstorms, then showers likely after 8pm. Cloudy, with a low around 64. East wind around 6 mph. Chance of precipitation is 70%. New precipitation amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

    Low: 64 °F

    Showers
    Likely

  • Thursday

    Thursday: Showers likely, with thunderstorms also possible after 2pm. Cloudy, with a high near 75. South wind 7 to 10 mph. Chance of precipitation is 70%. New rainfall amounts between a quarter and half of an inch possible.

    High: 75 °F

    Showers
    Likely

  • Thursday Night

    Thursday Night: Showers. Low around 65. Chance of precipitation is 80%. New precipitation amounts between a quarter and half of an inch possible.

    Low: 65 °F

    Showers

  • Friday

    Friday: Showers likely, mainly before 8am. Mostly cloudy, with a high near 76. Chance of precipitation is 60%.

    High: 76 °F

    Showers
    Likely

  • Friday Night

    Friday Night: A 40 percent chance of showers. Mostly cloudy, with a low around 62.

    Low: 62 °F

    Chance
    Showers

  • Saturday

    Saturday: A 30 percent chance of showers. Partly sunny, with a high near 77.

    High: 77 °F

    Chance
    Showers

Detailed Forecast

Today
A slight chance of showers between 2pm and 5pm, then a slight chance of showers and thunderstorms after 5pm. Mostly sunny, with a high near 79. Southwest wind 6 to 10 mph. Chance of precipitation is 20%.
Tonight
A chance of showers and thunderstorms. Mostly cloudy, with a low around 65. South wind 6 to 8 mph. Chance of precipitation is 50%.
Wednesday
A chance of showers, with thunderstorms also possible after 2pm. Mostly cloudy, with a high near 76. Northwest wind 5 to 7 mph becoming east in the afternoon. Chance of precipitation is 40%.
Wednesday Night
A chance of showers and thunderstorms, then showers likely after 8pm. Cloudy, with a low around 64. East wind around 6 mph. Chance of precipitation is 70%. New precipitation amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Thursday
Showers likely, with thunderstorms also possible after 2pm. Cloudy, with a high near 75. South wind 7 to 10 mph. Chance of precipitation is 70%. New rainfall amounts between a quarter and half of an inch possible.
Thursday Night
Showers. Low around 65. Chance of precipitation is 80%. New precipitation amounts between a quarter and half of an inch possible.
Friday
Showers likely, mainly before 8am. Mostly cloudy, with a high near 76. Chance of precipitation is 60%.
Friday Night
A 40 percent chance of showers. Mostly cloudy, with a low around 62.
Saturday
A 30 percent chance of showers. Partly sunny, with a high near 77.
Saturday Night
A 30 percent chance of showers. Mostly cloudy, with a low around 63.
Sunday
Mostly sunny, with a high near 77.
Sunday Night
Partly cloudy, with a low around 59.
Monday
Mostly sunny, with a high near 74.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Port Jefferson Station NY
 40.93°N 73.06°W (Elev. 161 ft)
Last Update:
1:43 am EDT Sep 23, 2025
Forecast Valid:
7am EDT Sep 23, 2025-6pm EDT Sep 29, 2025
 
Forecast Discussion
 
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Additional Resources

Radar & Satellite Image

Link to Local Radar Data Link to Satellite Data

Hourly Weather Forecast

National Digital Forecast Database

National Digital Forecast Database Maximum Temperature Forecast

High Temperature

National Digital Forecast Database Weather Element Forecast

Chance of Precipitation