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

70°F

21°C

Humidity 97%
Wind Speed Calm
Barometer 29.84 in (1010.3 mb)
Dewpoint 69°F (21°C)
Visibility 10.00 mi
Last update 18 Aug 1:56 am EDT
Extended Forecast for

Central Islip NY

  • Overnight

    Overnight: Mostly cloudy, with a low around 70. Calm wind.

    Low: 70 °F

    Mostly Cloudy

  • Tuesday

    Tuesday: Partly sunny, with a high near 84. Calm wind becoming northwest around 5 mph in the afternoon.

    High: 84 °F

    Partly Sunny

  • Tuesday Night

    Tuesday Night: Partly cloudy, with a low around 68. Calm wind.

    Low: 68 °F

    Partly Cloudy

  • Wednesday

    Wednesday: Sunny, with a high near 86. Calm wind becoming southwest 5 to 8 mph in the afternoon.

    High: 86 °F

    Sunny

  • Wednesday Night

    Wednesday Night: Partly cloudy, with a low around 70. Southwest wind 3 to 6 mph.

    Low: 70 °F

    Partly Cloudy

  • Thursday

    Thursday: A 40 percent chance of showers after 2pm. Mostly sunny, with a high near 83.

    High: 83 °F

    Mostly Sunny
    then Chance
    Showers

  • Thursday Night

    Thursday Night: A 50 percent chance of showers. Mostly cloudy, with a low around 65.

    Low: 65 °F

    Chance
    Showers

  • Friday

    Friday: A 30 percent chance of showers before 2pm. Partly sunny, with a high near 81.

    High: 81 °F

    Chance
    Showers

  • Friday Night

    Friday Night: A 30 percent chance of showers after 2am. Mostly cloudy, with a low around 65.

    Low: 65 °F

    Mostly Cloudy
    then Chance
    Showers

Detailed Forecast

Overnight
Mostly cloudy, with a low around 70. Calm wind.
Tuesday
Partly sunny, with a high near 84. Calm wind becoming northwest around 5 mph in the afternoon.
Tuesday Night
Partly cloudy, with a low around 68. Calm wind.
Wednesday
Sunny, with a high near 86. Calm wind becoming southwest 5 to 8 mph in the afternoon.
Wednesday Night
Partly cloudy, with a low around 70. Southwest wind 3 to 6 mph.
Thursday
A 40 percent chance of showers after 2pm. Mostly sunny, with a high near 83.
Thursday Night
A 50 percent chance of showers. Mostly cloudy, with a low around 65.
Friday
A 30 percent chance of showers before 2pm. Partly sunny, with a high near 81.
Friday Night
A 30 percent chance of showers after 2am. Mostly cloudy, with a low around 65.
Saturday
A 50 percent chance of showers. Mostly cloudy, with a high near 80.
Saturday Night
Showers likely. Mostly cloudy, with a low around 65. Chance of precipitation is 60%.
Sunday
A 50 percent chance of showers. Partly sunny, with a high near 81.
Sunday Night
A 30 percent chance of showers. Mostly cloudy, with a low around 64.
Monday
Mostly sunny, with a high near 81.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Central Islip NY
 40.79°N 73.2°W (Elev. 98 ft)
Last Update:
2:14 am EDT Aug 18, 2026
Forecast Valid:
2am EDT Aug 18, 2026-6pm EDT Aug 24, 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