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

25°F

-4°C

Humidity 69%
Wind Speed Calm
Barometer 30.56 in (1035.0 mb)
Dewpoint 16°F (-9°C)
Visibility 10.00 mi
Last update 29 Mar 5:56 am EDT
Extended Forecast for

Islip, Long Island Mac Arthur Airport NY

  • Today

    Today: Mostly sunny, with a high near 48. Light south wind becoming southwest 11 to 16 mph in the morning.

    High: 48 °F

    Mostly Sunny

  • Tonight

    Tonight: Increasing clouds, with a low around 40. Southwest wind around 15 mph.

    Low: 40 °F

    Increasing
    Clouds

  • Monday

    Monday: A 20 percent chance of showers after 2pm. Partly sunny, with a high near 58. Southwest wind 14 to 18 mph.

    High: 58 °F

    Partly Sunny
    then Slight
    Chance
    Showers

  • Monday Night

    Monday Night: A slight chance of showers before 8pm, then a slight chance of showers after 2am. Mostly cloudy, with a low around 47. Southwest wind 9 to 13 mph. Chance of precipitation is 20%.

    Low: 47 °F

    Mostly Cloudy
    then Slight
    Chance
    Showers

  • Tuesday

    Tuesday: A 20 percent chance of showers before 2pm. Partly sunny, with a high near 64. Southwest wind 10 to 17 mph.

    High: 64 °F

    Slight Chance
    Showers

  • Tuesday Night

    Tuesday Night: Partly cloudy, with a low around 51.

    Low: 51 °F

    Partly Cloudy

  • Wednesday

    Wednesday: A 50 percent chance of showers after 2pm. Mostly sunny, with a high near 65.

    High: 65 °F

    Mostly Sunny
    then Chance
    Showers

  • Wednesday Night

    Wednesday Night: Rain likely. Mostly cloudy, with a low around 42. Chance of precipitation is 70%.

    Low: 42 °F

    Rain Likely

  • Thursday

    Thursday: A 50 percent chance of rain. Mostly cloudy, with a high near 51.

    High: 51 °F

    Chance Rain

Detailed Forecast

Today
Mostly sunny, with a high near 48. Light south wind becoming southwest 11 to 16 mph in the morning.
Tonight
Increasing clouds, with a low around 40. Southwest wind around 15 mph.
Monday
A 20 percent chance of showers after 2pm. Partly sunny, with a high near 58. Southwest wind 14 to 18 mph.
Monday Night
A slight chance of showers before 8pm, then a slight chance of showers after 2am. Mostly cloudy, with a low around 47. Southwest wind 9 to 13 mph. Chance of precipitation is 20%.
Tuesday
A 20 percent chance of showers before 2pm. Partly sunny, with a high near 64. Southwest wind 10 to 17 mph.
Tuesday Night
Partly cloudy, with a low around 51.
Wednesday
A 50 percent chance of showers after 2pm. Mostly sunny, with a high near 65.
Wednesday Night
Rain likely. Mostly cloudy, with a low around 42. Chance of precipitation is 70%.
Thursday
A 50 percent chance of rain. Mostly cloudy, with a high near 51.
Thursday Night
A 50 percent chance of rain. Cloudy, with a low around 39.
Friday
Rain likely. Cloudy, with a high near 50. Chance of precipitation is 60%.
Friday Night
A 50 percent chance of rain. Cloudy, with a low around 40.
Saturday
A 40 percent chance of rain. Cloudy, with a high near 51.
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ABOUT THIS FORECAST

 
Point Forecast:
Islip, Long Island Mac Arthur Airport NY
 40.81°N 73.11°W (Elev. 98 ft)
Last Update:
2:25 am EDT Mar 29, 2026
Forecast Valid:
6am EDT Mar 29, 2026-6pm EDT Apr 4, 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