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.

Overcast

39°F

4°C

Humidity 89%
Wind Speed N 14 mph
Barometer 29.89 in (1012.3 mb)
Dewpoint 36°F (2°C)
Visibility 8.00 mi
Wind Chill31°F (-1°C)
Last update 23 Mar 3:56 pm EDT
Extended Forecast for

Islip, Long Island Mac Arthur Airport NY

  • This Afternoon

    This Afternoon: A 20 percent chance of showers. Mostly cloudy, with a steady temperature around 41. North wind 7 to 9 mph.

    High: 41 °F

    Slight Chance
    Showers

  • Tonight

    Tonight: Mostly cloudy, then gradually becoming mostly clear, with a low around 30. Northwest wind 5 to 9 mph, with gusts as high as 20 mph.

    Low: 30 °F

    Decreasing
    Clouds

  • Tuesday

    Tuesday: Sunny, with a high near 45. Wind chill values between 20 and 30 early. North wind 3 to 8 mph.

    High: 45 °F

    Sunny

  • Tuesday Night

    Tuesday Night: Mostly clear during the early evening, then becoming mostly cloudy, with a low around 34. South wind around 6 mph.

    Low: 34 °F

    Mostly Cloudy

  • Wednesday

    Wednesday: Partly sunny, with a high near 49. Light west wind becoming south 5 to 10 mph in the morning.

    High: 49 °F

    Partly Sunny

  • Wednesday Night

    Wednesday Night: Cloudy, with a low around 39.

    Low: 39 °F

    Cloudy

  • Thursday

    Thursday: Mostly cloudy, with a high near 55.

    High: 55 °F

    Mostly Cloudy

  • Thursday Night

    Thursday Night: Rain likely, mainly after 2am. Mostly cloudy, with a low around 43. Chance of precipitation is 60%.

    Low: 43 °F

    Chance Rain
    then Rain
    Likely

  • Friday

    Friday: Rain likely, mainly before 8am. Mostly cloudy, with a high near 54. Chance of precipitation is 60%.

    High: 54 °F

    Rain Likely

Detailed Forecast

This Afternoon
A 20 percent chance of showers. Mostly cloudy, with a steady temperature around 41. North wind 7 to 9 mph.
Tonight
Mostly cloudy, then gradually becoming mostly clear, with a low around 30. Northwest wind 5 to 9 mph, with gusts as high as 20 mph.
Tuesday
Sunny, with a high near 45. Wind chill values between 20 and 30 early. North wind 3 to 8 mph.
Tuesday Night
Mostly clear during the early evening, then becoming mostly cloudy, with a low around 34. South wind around 6 mph.
Wednesday
Partly sunny, with a high near 49. Light west wind becoming south 5 to 10 mph in the morning.
Wednesday Night
Cloudy, with a low around 39.
Thursday
Mostly cloudy, with a high near 55.
Thursday Night
Rain likely, mainly after 2am. Mostly cloudy, with a low around 43. Chance of precipitation is 60%.
Friday
Rain likely, mainly before 8am. Mostly cloudy, with a high near 54. Chance of precipitation is 60%.
Friday Night
Partly cloudy, with a low around 26.
Saturday
Mostly sunny, with a high near 41.
Saturday Night
Mostly clear, with a low around 30.
Sunday
Sunny, with a high near 47.
Sunday Night
Partly cloudy, with a low around 36.
Monday
Mostly sunny, with a high near 51.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Islip, Long Island Mac Arthur Airport NY
 40.78°N 73.09°W (Elev. 49 ft)
Last Update:
2:20 pm EDT Mar 23, 2026
Forecast Valid:
4pm EDT Mar 23, 2026-6pm EDT Mar 30, 2026
 
Forecast Discussion
 
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Additional Resources

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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