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

72°F

22°C

Humidity 97%
Wind Speed W 5 mph
Barometer 29.88 in (1011.6 mb)
Dewpoint 71°F (22°C)
Visibility 10.00 mi
Last update 19 Aug 1:56 am EDT
Extended Forecast for

Islip Terrace NY

  • Overnight

    Overnight: Partly cloudy, with a low around 69. Calm wind.

    Low: 69 °F

    Partly Cloudy

  • Wednesday

    Wednesday: Sunny, with a high near 85. Calm wind becoming south 5 to 9 mph in the afternoon.

    High: 85 °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: Showers likely and possibly a thunderstorm, mainly after 2pm. Mostly sunny, with a high near 82. Northwest wind 3 to 6 mph. Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

    High: 82 °F

    Slight Chance
    Showers then
    Showers
    Likely

  • Thursday Night

    Thursday Night: Showers likely and possibly a thunderstorm before 8pm, then a chance of showers between 8pm and 2am. Cloudy, then gradually becoming partly cloudy, with a low around 65. Calm wind becoming north around 5 mph after midnight. Chance of precipitation is 60%. New precipitation amounts between a quarter and half of an inch possible.

    Low: 65 °F

    Showers
    Likely

  • Friday

    Friday: Mostly sunny, with a high near 81.

    High: 81 °F

    Mostly Sunny

  • Friday Night

    Friday Night: A 30 percent chance of showers after 2am. Mostly cloudy, with a low around 64.

    Low: 64 °F

    Partly Cloudy
    then Chance
    Showers

  • Saturday

    Saturday: A 50 percent chance of showers. Mostly cloudy, with a high near 79.

    High: 79 °F

    Chance
    Showers

  • Saturday Night

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

    Low: 65 °F

    Chance
    Showers

Detailed Forecast

Overnight
Partly cloudy, with a low around 69. Calm wind.
Wednesday
Sunny, with a high near 85. Calm wind becoming south 5 to 9 mph in the afternoon.
Wednesday Night
Partly cloudy, with a low around 70. Southwest wind 3 to 6 mph.
Thursday
Showers likely and possibly a thunderstorm, mainly after 2pm. Mostly sunny, with a high near 82. Northwest wind 3 to 6 mph. Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Thursday Night
Showers likely and possibly a thunderstorm before 8pm, then a chance of showers between 8pm and 2am. Cloudy, then gradually becoming partly cloudy, with a low around 65. Calm wind becoming north around 5 mph after midnight. Chance of precipitation is 60%. New precipitation amounts between a quarter and half of an inch possible.
Friday
Mostly sunny, with a high near 81.
Friday Night
A 30 percent chance of showers after 2am. Mostly cloudy, with a low around 64.
Saturday
A 50 percent chance of showers. Mostly cloudy, with a high near 79.
Saturday Night
A 50 percent chance of showers. Mostly cloudy, with a low around 65.
Sunday
A 30 percent chance of showers. Partly sunny, with a high near 82.
Sunday Night
Partly cloudy, with a low around 65.
Monday
Mostly sunny, with a high near 82.
Monday Night
Mostly clear, with a low around 63.
Tuesday
Sunny, with a high near 81.
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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:
2:14 am EDT Aug 19, 2026
Forecast Valid:
2am EDT Aug 19, 2026-6pm EDT Aug 25, 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