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

67°F

19°C

Humidity 61%
Wind Speed SW 5 mph
Barometer 30.07 in (1018.1 mb)
Dewpoint 53°F (12°C)
Visibility 10.00 mi
Last update 1 Apr 4:56 pm EDT
Extended Forecast for

2 Miles NNW Stony Brook NY

  • This Afternoon

    This Afternoon: Showers and possibly a thunderstorm. Steady temperature around 62. North wind around 6 mph. Chance of precipitation is 80%.

    High: 62 °F

    Showers

  • Tonight

    Tonight: Showers and possibly a thunderstorm. Low around 42. East wind 5 to 15 mph. Chance of precipitation is 90%. New precipitation amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

    Low: 42 °F

    Showers

  • Thursday

    Thursday: Showers likely, mainly before 11am. Cloudy, with a high near 47. East wind 14 to 16 mph. Chance of precipitation is 60%.

    High: 47 °F

    Showers
    Likely then
    Slight Chance
    Showers

  • Thursday Night

    Thursday Night: A 20 percent chance of showers after 8pm. Cloudy, with a low around 40. East wind 8 to 13 mph.

    Low: 40 °F

    Slight Chance
    Showers

  • Friday

    Friday: Cloudy, then gradually becoming mostly sunny, with a high near 59. East wind 5 to 8 mph becoming southwest in the afternoon.

    High: 59 °F

    Decreasing
    Clouds

  • Friday Night

    Friday Night: Mostly cloudy, with a low around 51.

    Low: 51 °F

    Mostly Cloudy

  • Saturday

    Saturday: Mostly sunny, with a high near 65.

    High: 65 °F

    Mostly Sunny

  • Saturday Night

    Saturday Night: A 30 percent chance of showers after 2am. Mostly cloudy, with a low around 47.

    Low: 47 °F

    Mostly Cloudy
    then Chance
    Showers

  • Sunday

    Sunday: Showers, mainly after 8am. High near 60. Chance of precipitation is 80%.

    High: 60 °F

    Showers

Detailed Forecast

This Afternoon
Showers and possibly a thunderstorm. Steady temperature around 62. North wind around 6 mph. Chance of precipitation is 80%.
Tonight
Showers and possibly a thunderstorm. Low around 42. East wind 5 to 15 mph. Chance of precipitation is 90%. New precipitation amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Thursday
Showers likely, mainly before 11am. Cloudy, with a high near 47. East wind 14 to 16 mph. Chance of precipitation is 60%.
Thursday Night
A 20 percent chance of showers after 8pm. Cloudy, with a low around 40. East wind 8 to 13 mph.
Friday
Cloudy, then gradually becoming mostly sunny, with a high near 59. East wind 5 to 8 mph becoming southwest in the afternoon.
Friday Night
Mostly cloudy, with a low around 51.
Saturday
Mostly sunny, with a high near 65.
Saturday Night
A 30 percent chance of showers after 2am. Mostly cloudy, with a low around 47.
Sunday
Showers, mainly after 8am. High near 60. Chance of precipitation is 80%.
Sunday Night
Showers, mainly before 8pm. Low around 41. Chance of precipitation is 80%.
Monday
Mostly sunny, with a high near 53.
Monday Night
Mostly clear, with a low around 39.
Tuesday
Mostly sunny, with a high near 51.
Tuesday Night
Partly cloudy, with a low around 34.
Wednesday
Sunny, with a high near 48.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
2 Miles NNW Stony Brook NY
 40.92°N 73.15°W (Elev. 36 ft)
Last Update:
2:31 pm EDT Apr 1, 2026
Forecast Valid:
5pm EDT Apr 1, 2026-6pm EDT Apr 8, 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