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

53°F

12°C

Humidity 52%
Wind Speed N 20 G 30 mph
Barometer 29.89 in (1012.0 mb)
Dewpoint 36°F (2°C)
Visibility 10.00 mi
Wind Chill48°F (9°C)
Last update 21 Mar 12:56 pm EDT
Extended Forecast for

2 Miles NNW Stony Brook NY

  • This Afternoon

    This Afternoon: Mostly sunny, with a high near 54. North wind 7 to 9 mph.

    High: 54 °F

    Mostly Sunny

  • Tonight

    Tonight: Increasing clouds, with a low around 40. Light and variable wind becoming southeast around 5 mph after midnight.

    Low: 40 °F

    Increasing
    Clouds

  • Sunday

    Sunday: A 30 percent chance of rain after 2pm. Mostly cloudy, with a high near 55. Southwest wind 8 to 10 mph.

    High: 55 °F

    Mostly Cloudy
    then Chance
    Rain

  • Sunday Night

    Sunday Night: Rain, mainly after 8pm. Low around 39. Southwest wind 6 to 9 mph becoming north after midnight. Chance of precipitation is 80%. New precipitation amounts between a quarter and half of an inch possible.

    Low: 39 °F

    Rain

  • Monday

    Monday: A 40 percent chance of rain before 2pm. Cloudy, then gradually becoming mostly sunny, with a high near 47. North wind 11 to 13 mph.

    High: 47 °F

    Chance Rain

  • Monday Night

    Monday Night: Mostly clear, with a low around 31.

    Low: 31 °F

    Mostly Clear

  • Tuesday

    Tuesday: Sunny, with a high near 45.

    High: 45 °F

    Sunny

  • Tuesday Night

    Tuesday Night: Mostly cloudy, with a low around 36.

    Low: 36 °F

    Mostly Cloudy

  • Wednesday

    Wednesday: Partly sunny, with a high near 50.

    High: 50 °F

    Partly Sunny

Detailed Forecast

This Afternoon
Mostly sunny, with a high near 54. North wind 7 to 9 mph.
Tonight
Increasing clouds, with a low around 40. Light and variable wind becoming southeast around 5 mph after midnight.
Sunday
A 30 percent chance of rain after 2pm. Mostly cloudy, with a high near 55. Southwest wind 8 to 10 mph.
Sunday Night
Rain, mainly after 8pm. Low around 39. Southwest wind 6 to 9 mph becoming north after midnight. Chance of precipitation is 80%. New precipitation amounts between a quarter and half of an inch possible.
Monday
A 40 percent chance of rain before 2pm. Cloudy, then gradually becoming mostly sunny, with a high near 47. North wind 11 to 13 mph.
Monday Night
Mostly clear, with a low around 31.
Tuesday
Sunny, with a high near 45.
Tuesday Night
Mostly cloudy, with a low around 36.
Wednesday
Partly sunny, with a high near 50.
Wednesday Night
Mostly cloudy, with a low around 36.
Thursday
Mostly cloudy, with a high near 49.
Thursday Night
Rain likely. Mostly cloudy, with a low around 39. Chance of precipitation is 60%.
Friday
Rain likely. Partly sunny, with a high near 50. Chance of precipitation is 60%.
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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:
9:57 am EDT Mar 21, 2026
Forecast Valid:
1pm EDT Mar 21, 2026-6pm EDT Mar 27, 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