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.

Fair

25°F

-4°C

Humidity 66%
Wind Speed Calm
Barometer 30.55 in (1034.4 mb)
Dewpoint 15°F (-9°C)
Visibility 10.00 mi
Last update 29 Mar 3:56 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 8 to 13 mph in the morning.

    High: 48 °F

    Mostly Sunny

  • Tonight

    Tonight: Increasing clouds, with a low around 40. Southwest wind 9 to 11 mph, with gusts as high as 23 mph.

    Low: 40 °F

    Increasing
    Clouds

  • Monday

    Monday: A 20 percent chance of showers after 2pm. Partly sunny, with a high near 56. Southwest wind 10 to 14 mph, with gusts as high as 24 mph.

    High: 56 °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 6 to 9 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 63. Southwest wind 7 to 15 mph.

    High: 63 °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 8 to 13 mph in the morning.
Tonight
Increasing clouds, with a low around 40. Southwest wind 9 to 11 mph, with gusts as high as 23 mph.
Monday
A 20 percent chance of showers after 2pm. Partly sunny, with a high near 56. Southwest wind 10 to 14 mph, with gusts as high as 24 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 6 to 9 mph. Chance of precipitation is 20%.
Tuesday
A 20 percent chance of showers before 2pm. Partly sunny, with a high near 63. Southwest wind 7 to 15 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 51. Chance of precipitation is 60%.
Friday Night
Rain likely. Cloudy, with a low around 40. Chance of precipitation is 60%.
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
 40.8°N 73.09°W (Elev. 98 ft)
Last Update:
2:25 am EDT Mar 29, 2026
Forecast Valid:
4am EDT Mar 29, 2026-6pm EDT Apr 4, 2026
 
Forecast Discussion
 
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Additional Resources

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Hourly Weather Forecast

National Digital Forecast Database

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High Temperature

National Digital Forecast Database Weather Element Forecast

Chance of Precipitation