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.

Mostly Cloudy

77°F

25°C

Humidity 88%
Wind Speed SE 7 mph
Barometer 30.06 in (1017.8 mb)
Dewpoint 73°F (23°C)
Visibility 10.00 mi
Heat Index78°F (26°C)
Last update 14 Jul 6:56 am EDT
Extended Forecast for

Islip Terrace NY

  • Today

    Today: A 30 percent chance of showers and thunderstorms, mainly after 5pm. Patchy fog before 8am. Otherwise, mostly cloudy, with a high near 82. Light south wind increasing to 5 to 9 mph in the morning.

    High: 82 °F

    Patchy
    Showers and
    Patchy Fog
    then Chance
    T-storms

  • Tonight

    Tonight: A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 2am. Mostly cloudy, with a low around 73. Southwest wind 3 to 7 mph. Chance of precipitation is 60%. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

    Low: 73 °F

    Chance
    T-storms then
    Showers
    Likely

  • Tuesday

    Tuesday: Showers likely and possibly a thunderstorm before 8am, then a chance of showers and thunderstorms, mainly between 8am and 2pm. Cloudy, then gradually becoming mostly sunny, with a high near 84. Calm wind becoming south 5 to 7 mph in the afternoon. Chance of precipitation is 60%. New rainfall amounts between a quarter and half of an inch possible.

    High: 84 °F

    Showers
    Likely

  • Tuesday Night

    Tuesday Night: A 20 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 73. Southwest wind 3 to 6 mph.

    Low: 73 °F

    Slight Chance
    T-storms

  • Wednesday

    Wednesday: A 20 percent chance of showers and thunderstorms. Partly sunny, with a high near 86. Light south wind increasing to 6 to 11 mph in the morning.

    High: 86 °F

    Slight Chance
    T-storms

  • Wednesday Night

    Wednesday Night: A 30 percent chance of showers. Mostly cloudy, with a low around 75.

    Low: 75 °F

    Chance
    Showers

  • Thursday

    Thursday: A 40 percent chance of showers and thunderstorms after 2pm. Partly sunny, with a high near 88.

    High: 88 °F

    Partly Sunny
    then Chance
    T-storms

  • Thursday Night

    Thursday Night: A 30 percent chance of showers and thunderstorms before 8pm. Mostly cloudy, with a low around 75.

    Low: 75 °F

    Chance
    T-storms then
    Partly Cloudy

  • Friday

    Friday: A 40 percent chance of showers and thunderstorms after 2pm. Mostly sunny, with a high near 90.

    High: 90 °F

    Mostly Sunny
    then Chance
    T-storms

Detailed Forecast

Today
A 30 percent chance of showers and thunderstorms, mainly after 5pm. Patchy fog before 8am. Otherwise, mostly cloudy, with a high near 82. Light south wind increasing to 5 to 9 mph in the morning.
Tonight
A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 2am. Mostly cloudy, with a low around 73. Southwest wind 3 to 7 mph. Chance of precipitation is 60%. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.
Tuesday
Showers likely and possibly a thunderstorm before 8am, then a chance of showers and thunderstorms, mainly between 8am and 2pm. Cloudy, then gradually becoming mostly sunny, with a high near 84. Calm wind becoming south 5 to 7 mph in the afternoon. Chance of precipitation is 60%. New rainfall amounts between a quarter and half of an inch possible.
Tuesday Night
A 20 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 73. Southwest wind 3 to 6 mph.
Wednesday
A 20 percent chance of showers and thunderstorms. Partly sunny, with a high near 86. Light south wind increasing to 6 to 11 mph in the morning.
Wednesday Night
A 30 percent chance of showers. Mostly cloudy, with a low around 75.
Thursday
A 40 percent chance of showers and thunderstorms after 2pm. Partly sunny, with a high near 88.
Thursday Night
A 30 percent chance of showers and thunderstorms before 8pm. Mostly cloudy, with a low around 75.
Friday
A 40 percent chance of showers and thunderstorms after 2pm. Mostly sunny, with a high near 90.
Friday Night
A 30 percent chance of showers and thunderstorms before 8pm. Mostly cloudy, with a low around 72.
Saturday
Mostly sunny, with a high near 86.
Saturday Night
Partly cloudy, with a low around 71.
Sunday
A 30 percent chance of showers. Mostly sunny, with a high near 84.
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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:
6:50 am EDT Jul 14, 2025
Forecast Valid:
7am EDT Jul 14, 2025-6pm EDT Jul 20, 2025
 
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