Current conditions at

Islip, Long Island Mac Arthur Airport (KISP)

Lat: 40.79°NLon: 73.1°WElev: 98ft.

Fair

31°F

-1°C

Humidity 67%
Wind Speed NE 7 mph
Barometer 29.96 in (1014.4 mb)
Dewpoint 21°F (-6°C)
Visibility 10.00 mi
Wind Chill24°F (-4°C)
Last update 27 Feb 12:56 am EST
Extended Forecast for

Port Jefferson NY

  • Overnight

    Overnight: Mostly clear, with a low around 25. North wind 3 to 5 mph.

    Low: 25 °F

    Mostly Clear

  • Friday

    Friday: Sunny, with a high near 41. Calm wind becoming south around 5 mph.

    High: 41 °F

    Sunny

  • Friday Night

    Friday Night: Mostly clear, with a low around 28. Light south wind.

    Low: 28 °F

    Mostly Clear

  • Saturday

    Saturday: Mostly sunny, with a high near 47. Southwest wind 3 to 6 mph.

    High: 47 °F

    Mostly Sunny

  • Saturday Night

    Saturday Night: Partly cloudy, with a low around 29. Calm wind becoming north around 5 mph after midnight.

    Low: 29 °F

    Partly Cloudy

  • Sunday

    Sunday: Scattered snow showers before 1pm.  Cloudy, then gradual clearing during the afternoon, with a high near 36. Chance of precipitation is 40%.

    High: 36 °F

    Scattered
    Snow Showers

  • Sunday Night

    Sunday Night: Partly cloudy, with a low around 16.

    Low: 16 °F

    Partly Cloudy

  • Monday

    Monday: Mostly cloudy, with a high near 27.

    High: 27 °F

    Mostly Cloudy

  • Monday Night

    Monday Night: Mostly cloudy, with a low around 19.

    Low: 19 °F

    Mostly Cloudy

Detailed Forecast

Overnight
Mostly clear, with a low around 25. North wind 3 to 5 mph.
Friday
Sunny, with a high near 41. Calm wind becoming south around 5 mph.
Friday Night
Mostly clear, with a low around 28. Light south wind.
Saturday
Mostly sunny, with a high near 47. Southwest wind 3 to 6 mph.
Saturday Night
Partly cloudy, with a low around 29. Calm wind becoming north around 5 mph after midnight.
Sunday
Scattered snow showers before 1pm. Cloudy, then gradual clearing during the afternoon, with a high near 36. Chance of precipitation is 40%.
Sunday Night
Partly cloudy, with a low around 16.
Monday
Mostly cloudy, with a high near 27.
Monday Night
Mostly cloudy, with a low around 19.
Tuesday
A chance of rain and snow after 1pm. Mostly cloudy, with a high near 36. Chance of precipitation is 30%.
Tuesday Night
Rain likely. Cloudy, with a low around 30. Chance of precipitation is 70%.
Wednesday
A 30 percent chance of rain. Partly sunny, with a high near 42.
Wednesday Night
Mostly cloudy, with a low around 32.
Thursday
A 30 percent chance of rain. Mostly cloudy, with a high near 44.
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ABOUT THIS FORECAST

 
Point Forecast:
Port Jefferson NY
 40.93°N 73.06°W (Elev. 161 ft)
12:50 am EST Feb 27, 2026
1am EST Feb 27, 2026-6pm EST Mar 5, 2026
 
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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