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.

A Few Clouds

19°F

-7°C

Humidity 71%
Wind Speed Calm
Barometer 30.65 in (1038.2 mb)
Dewpoint 11°F (-12°C)
Visibility 10.00 mi
Last update 2 Mar 9:56 pm EST
Extended Forecast for

Port Jefferson Station NY

  • Tonight

    Tonight: Increasing clouds, with a low around 22. Calm wind.

    Low: 22 °F

    Increasing
    Clouds

  • Tuesday

    Tuesday: A chance of snow before 10am, then rain likely, possibly mixed with snow between 10am and 1pm, then rain after 1pm. High near 39. Wind chill values between 25 and 35. Southeast wind 3 to 7 mph. Chance of precipitation is 90%. Little or no snow accumulation expected.

    High: 39 °F

    Rain/Snow

  • Tuesday Night

    Tuesday Night: Rain. Low around 36. Light and variable wind becoming southwest around 6 mph in the evening. Chance of precipitation is 100%. New precipitation amounts between a quarter and half of an inch possible.

    Low: 36 °F

    Rain

  • Wednesday

    Wednesday: Cloudy, then gradually becoming mostly sunny, with a high near 45. Light west wind.

    High: 45 °F

    Decreasing
    Clouds

  • Wednesday Night

    Wednesday Night: A 40 percent chance of rain, mainly after 1am. Mostly cloudy, with a low around 33. Calm wind.

    Low: 33 °F

    Chance Rain

  • Thursday

    Thursday: A 40 percent chance of rain before 1pm. Cloudy, with a high near 44.

    High: 44 °F

    Chance Rain

  • Thursday Night

    Thursday Night: Rain, mainly after 1am. Low around 36. Chance of precipitation is 80%.

    Low: 36 °F

    Chance Rain
    then Rain

  • Friday

    Friday: A 50 percent chance of rain before 1pm. Cloudy, with a high near 43.

    High: 43 °F

    Chance Rain

  • Friday Night

    Friday Night: Mostly cloudy, with a low around 34.

    Low: 34 °F

    Mostly Cloudy

Detailed Forecast

Tonight
Increasing clouds, with a low around 22. Calm wind.
Tuesday
A chance of snow before 10am, then rain likely, possibly mixed with snow between 10am and 1pm, then rain after 1pm. High near 39. Wind chill values between 25 and 35. Southeast wind 3 to 7 mph. Chance of precipitation is 90%. Little or no snow accumulation expected.
Tuesday Night
Rain. Low around 36. Light and variable wind becoming southwest around 6 mph in the evening. Chance of precipitation is 100%. New precipitation amounts between a quarter and half of an inch possible.
Wednesday
Cloudy, then gradually becoming mostly sunny, with a high near 45. Light west wind.
Wednesday Night
A 40 percent chance of rain, mainly after 1am. Mostly cloudy, with a low around 33. Calm wind.
Thursday
A 40 percent chance of rain before 1pm. Cloudy, with a high near 44.
Thursday Night
Rain, mainly after 1am. Low around 36. Chance of precipitation is 80%.
Friday
A 50 percent chance of rain before 1pm. Cloudy, with a high near 43.
Friday Night
Mostly cloudy, with a low around 34.
Saturday
Mostly cloudy, with a high near 48.
Saturday Night
A 50 percent chance of rain. Mostly cloudy, with a low around 41.
Sunday
A 30 percent chance of rain. Mostly cloudy, with a high near 56.
Sunday Night
A 40 percent chance of rain. Mostly cloudy, with a low around 42.
Monday
Mostly cloudy, with a high near 54.
Basemap Options
Click map to change the forecast location
Loading map...
Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Port Jefferson Station NY
 40.93°N 73.06°W (Elev. 161 ft)
Last Update:
1:04 pm EST Mar 2, 2026
Forecast Valid:
10pm EST Mar 2, 2026-6pm EDT Mar 9, 2026
 
Forecast Discussion
 
Get as KML Get as XML

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