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

39°F

4°C

Humidity 89%
Wind Speed E 5 mph
Barometer 30.08 in (1018.7 mb)
Dewpoint 36°F (2°C)
Visibility 10.00 mi
Wind Chill35°F (2°C)
Last update 7 Apr 12:56 am EDT
Extended Forecast for

2 Miles NNW Stony Brook NY

  • Overnight

    Overnight: A 30 percent chance of showers, mainly after 2am. Mostly cloudy, with a low around 40. Southeast wind around 5 mph.

    Low: 40 °F

    Chance
    Showers

  • Tuesday

    Tuesday: A slight chance of showers before 8am, then a slight chance of showers after 2pm. Mostly sunny, with a high near 52. Northwest wind 8 to 16 mph. Chance of precipitation is 20%.

    High: 52 °F

    Partly Sunny
    then Slight
    Chance
    Showers

  • Tuesday Night

    Tuesday Night: Mostly clear, with a low around 31. Wind chill values between 20 and 25. North wind 11 to 14 mph.

    Low: 31 °F

    Mostly Clear

  • Wednesday

    Wednesday: Sunny, with a high near 48. Wind chill values between 20 and 30 early. Northeast wind 6 to 8 mph becoming east in the afternoon.

    High: 48 °F

    Sunny

  • Wednesday Night

    Wednesday Night: Mostly clear, with a low around 34. South wind 3 to 6 mph.

    Low: 34 °F

    Mostly Clear

  • Thursday

    Thursday: Mostly sunny, with a high near 52.

    High: 52 °F

    Mostly Sunny

  • Thursday Night

    Thursday Night: Partly cloudy, with a low around 42.

    Low: 42 °F

    Partly Cloudy

  • Friday

    Friday: Mostly sunny, with a high near 63.

    High: 63 °F

    Mostly Sunny

  • Friday Night

    Friday Night: Partly cloudy, with a low around 48.

    Low: 48 °F

    Partly Cloudy

Detailed Forecast

Overnight
A 30 percent chance of showers, mainly after 2am. Mostly cloudy, with a low around 40. Southeast wind around 5 mph.
Tuesday
A slight chance of showers before 8am, then a slight chance of showers after 2pm. Mostly sunny, with a high near 52. Northwest wind 8 to 16 mph. Chance of precipitation is 20%.
Tuesday Night
Mostly clear, with a low around 31. Wind chill values between 20 and 25. North wind 11 to 14 mph.
Wednesday
Sunny, with a high near 48. Wind chill values between 20 and 30 early. Northeast wind 6 to 8 mph becoming east in the afternoon.
Wednesday Night
Mostly clear, with a low around 34. South wind 3 to 6 mph.
Thursday
Mostly sunny, with a high near 52.
Thursday Night
Partly cloudy, with a low around 42.
Friday
Mostly sunny, with a high near 63.
Friday Night
Partly cloudy, with a low around 48.
Saturday
Mostly sunny, with a high near 67.
Saturday Night
Partly cloudy, with a low around 46.
Sunday
Mostly sunny, with a high near 60.
Sunday Night
Mostly cloudy, with a low around 48.
Monday
Partly sunny, with a high near 66.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
2 Miles NNW Stony Brook NY
 40.92°N 73.15°W (Elev. 36 ft)
Last Update:
8:00 pm EDT Apr 6, 2026
Forecast Valid:
1am EDT Apr 7, 2026-6pm EDT Apr 13, 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