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

63°F

17°C

Humidity 93%
Wind Speed Calm
Barometer 30.06 in (1018.0 mb)
Dewpoint 61°F (16°C)
Visibility 10.00 mi
Last update 26 Aug 6:56 am EDT
Extended Forecast for

Port Jefferson Station NY

  • Today

    Today: Sunny, with a high near 78. West wind 3 to 6 mph.

    High: 78 °F

    Sunny

  • Tonight

    Tonight: Partly cloudy, with a low around 67. South wind around 7 mph.

    Low: 67 °F

    Partly Cloudy

  • Thursday

    Thursday: A slight chance of showers between 11am and 2pm, then a chance of showers and thunderstorms after 2pm. Increasing clouds, with a high near 80. South wind 7 to 14 mph. Chance of precipitation is 30%.

    High: 80 °F

    Chance
    Showers

  • Thursday Night

    Thursday Night: A chance of showers and thunderstorms before 5am, then a slight chance of showers. Mostly cloudy, with a low around 68. South wind 5 to 10 mph becoming light southwest after midnight. Chance of precipitation is 50%.

    Low: 68 °F

    Chance
    Showers

  • Friday

    Friday: A slight chance of showers, with thunderstorms also possible after 11am. Partly sunny, with a high near 80. Southwest wind 3 to 5 mph. Chance of precipitation is 20%.

    High: 80 °F

    Slight Chance
    T-storms

  • Friday Night

    Friday Night: Mostly cloudy, with a low around 65.

    Low: 65 °F

    Mostly Cloudy

  • Saturday

    Saturday: Mostly sunny, with a high near 77.

    High: 77 °F

    Mostly Sunny

  • Saturday Night

    Saturday Night: Partly cloudy, with a low around 64.

    Low: 64 °F

    Partly Cloudy

  • Sunday

    Sunday: Sunny, with a high near 79.

    High: 79 °F

    Sunny

Detailed Forecast

Today
Sunny, with a high near 78. West wind 3 to 6 mph.
Tonight
Partly cloudy, with a low around 67. South wind around 7 mph.
Thursday
A slight chance of showers between 11am and 2pm, then a chance of showers and thunderstorms after 2pm. Increasing clouds, with a high near 80. South wind 7 to 14 mph. Chance of precipitation is 30%.
Thursday Night
A chance of showers and thunderstorms before 5am, then a slight chance of showers. Mostly cloudy, with a low around 68. South wind 5 to 10 mph becoming light southwest after midnight. Chance of precipitation is 50%.
Friday
A slight chance of showers, with thunderstorms also possible after 11am. Partly sunny, with a high near 80. Southwest wind 3 to 5 mph. Chance of precipitation is 20%.
Friday Night
Mostly cloudy, with a low around 65.
Saturday
Mostly sunny, with a high near 77.
Saturday Night
Partly cloudy, with a low around 64.
Sunday
Sunny, with a high near 79.
Sunday Night
Partly cloudy, with a low around 68.
Monday
Mostly sunny, with a high near 83.
Monday Night
Partly cloudy, with a low around 70.
Tuesday
Partly sunny, with a high near 83.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Port Jefferson Station NY
 40.93°N 73.06°W (Elev. 161 ft)
Last Update:
2:49 am EDT Aug 26, 2026
Forecast Valid:
7am EDT Aug 26, 2026-6pm EDT Sep 1, 2026
 
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