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

46°F

8°C

Humidity 83%
Wind Speed SE 3 mph
Barometer 29.99 in (1015.5 mb)
Dewpoint 41°F (5°C)
Visibility 10.00 mi
Last update 11 Mar 2:56 am EDT
Extended Forecast for

Islip Terrace NY

  • Overnight

    Overnight: Mostly clear, with a steady temperature around 47. Light south wind.

    Low: 47 °F

    Mostly Clear

  • Wednesday

    Wednesday: A 30 percent chance of showers after 2pm. Increasing clouds, with a high near 64. Light south wind increasing to 5 to 10 mph in the morning. Winds could gust as high as 20 mph.

    High: 64 °F

    Partly Sunny
    then Chance
    Showers

  • Wednesday Night

    Wednesday Night: A chance of showers and thunderstorms. Areas of fog before 3am. Otherwise, mostly cloudy, with a low around 40. South wind around 10 mph, with gusts as high as 26 mph. Chance of precipitation is 40%.

    Low: 40 °F

    Chance
    Showers and
    Areas Fog

  • Thursday

    Thursday: Showers likely, mainly between 8am and 2pm. Cloudy, with a temperature rising to near 53 by 10am, then falling to around 42 during the remainder of the day. Northwest wind 10 to 14 mph, with gusts as high as 24 mph. Chance of precipitation is 60%. New precipitation amounts of less than a tenth of an inch possible.

    High: 53 °F⇓

    Showers
    Likely

  • Thursday Night

    Thursday Night: Mostly cloudy, then gradually becoming mostly clear, with a low around 29. Northwest wind around 6 mph.

    Low: 29 °F

    Decreasing
    Clouds

  • Friday

    Friday: Increasing clouds, with a high near 46.

    High: 46 °F

    Increasing
    Clouds

  • Friday Night

    Friday Night: Mostly cloudy, then gradually becoming mostly clear, with a low around 36.

    Low: 36 °F

    Decreasing
    Clouds

  • Saturday

    Saturday: Sunny, with a high near 49.

    High: 49 °F

    Sunny

  • Saturday Night

    Saturday Night: Mostly cloudy, with a low around 32.

    Low: 32 °F

    Mostly Cloudy

Detailed Forecast

Overnight
Mostly clear, with a steady temperature around 47. Light south wind.
Wednesday
A 30 percent chance of showers after 2pm. Increasing clouds, with a high near 64. Light south wind increasing to 5 to 10 mph in the morning. Winds could gust as high as 20 mph.
Wednesday Night
A chance of showers and thunderstorms. Areas of fog before 3am. Otherwise, mostly cloudy, with a low around 40. South wind around 10 mph, with gusts as high as 26 mph. Chance of precipitation is 40%.
Thursday
Showers likely, mainly between 8am and 2pm. Cloudy, with a temperature rising to near 53 by 10am, then falling to around 42 during the remainder of the day. Northwest wind 10 to 14 mph, with gusts as high as 24 mph. Chance of precipitation is 60%. New precipitation amounts of less than a tenth of an inch possible.
Thursday Night
Mostly cloudy, then gradually becoming mostly clear, with a low around 29. Northwest wind around 6 mph.
Friday
Increasing clouds, with a high near 46.
Friday Night
Mostly cloudy, then gradually becoming mostly clear, with a low around 36.
Saturday
Sunny, with a high near 49.
Saturday Night
Mostly cloudy, with a low around 32.
Sunday
Cloudy, with a high near 49.
Sunday Night
Rain. Low around 40. Chance of precipitation is 80%.
Monday
Rain. High near 54. Chance of precipitation is 90%.
Monday Night
Rain likely. Mostly cloudy, with a low around 28. Chance of precipitation is 60%.
Tuesday
Mostly sunny, with a high near 40.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Islip Terrace NY
 40.75°N 73.18°W (Elev. 30 ft)
Last Update:
3:05 am EDT Mar 11, 2026
Forecast Valid:
3am EDT Mar 11, 2026-6pm EDT Mar 17, 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