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

49°F

9°C

Humidity 59%
Wind Speed S 20 G 30 mph
Barometer 30.00 in (1015.8 mb)
Dewpoint 35°F (2°C)
Visibility 10.00 mi
Wind Chill42°F (6°C)
Last update 20 Mar 1:56 pm EDT
Extended Forecast for

2 Miles NNW Stony Brook NY

  • This Afternoon

    This Afternoon: A 30 percent chance of rain after 5pm. Mostly cloudy, with a high near 53. South wind around 14 mph.

    High: 53 °F

    Chance Rain

  • Tonight

    Tonight: Rain, mainly before 2am. Low around 42. South wind 9 to 18 mph. Chance of precipitation is 80%. New precipitation amounts between a tenth and quarter of an inch possible.

    Low: 42 °F

    Rain

  • Saturday

    Saturday: Sunny, with a high near 52. Northwest wind 8 to 10 mph.

    High: 52 °F

    Sunny

  • Saturday Night

    Saturday Night: Mostly cloudy, with a low around 39. North wind around 6 mph becoming southeast after midnight.

    Low: 39 °F

    Mostly Cloudy

  • Sunday

    Sunday: A 20 percent chance of rain. Mostly cloudy, with a high near 53. South wind 6 to 10 mph.

    High: 53 °F

    Slight Chance
    Rain

  • Sunday Night

    Sunday Night: Rain likely, mainly after 2am. Cloudy, with a low around 40. Chance of precipitation is 60%. New precipitation amounts between a quarter and half of an inch possible.

    Low: 40 °F

    Rain Likely

  • Monday

    Monday: Rain likely, mainly before 8am. Cloudy, then gradually becoming mostly sunny, with a high near 48. Chance of precipitation is 60%.

    High: 48 °F

    Rain Likely

  • Monday Night

    Monday Night: Partly cloudy, with a low around 31.

    Low: 31 °F

    Partly Cloudy

  • Tuesday

    Tuesday: Sunny, with a high near 45.

    High: 45 °F

    Sunny

Detailed Forecast

This Afternoon
A 30 percent chance of rain after 5pm. Mostly cloudy, with a high near 53. South wind around 14 mph.
Tonight
Rain, mainly before 2am. Low around 42. South wind 9 to 18 mph. Chance of precipitation is 80%. New precipitation amounts between a tenth and quarter of an inch possible.
Saturday
Sunny, with a high near 52. Northwest wind 8 to 10 mph.
Saturday Night
Mostly cloudy, with a low around 39. North wind around 6 mph becoming southeast after midnight.
Sunday
A 20 percent chance of rain. Mostly cloudy, with a high near 53. South wind 6 to 10 mph.
Sunday Night
Rain likely, mainly after 2am. Cloudy, with a low around 40. Chance of precipitation is 60%. New precipitation amounts between a quarter and half of an inch possible.
Monday
Rain likely, mainly before 8am. Cloudy, then gradually becoming mostly sunny, with a high near 48. Chance of precipitation is 60%.
Monday Night
Partly cloudy, with a low around 31.
Tuesday
Sunny, with a high near 45.
Tuesday Night
Mostly cloudy, with a low around 35.
Wednesday
Mostly cloudy, with a high near 49.
Wednesday Night
Mostly cloudy, with a low around 33.
Thursday
A 30 percent chance of rain. Partly sunny, with a high near 49.
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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:
9:59 am EDT Mar 20, 2026
Forecast Valid:
2pm EDT Mar 20, 2026-6pm EDT Mar 26, 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