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

76°F

24°C

Humidity 91%
Wind Speed S 5 mph
Barometer 30.07 in (1018.0 mb)
Dewpoint 73°F (23°C)
Visibility 10.00 mi
Heat Index76°F (24°C)
Last update 14 Jul 5:56 am EDT
Extended Forecast for

Islip, Long Island Mac Arthur Airport NY

  • Today

    Today: Patchy drizzle before 2pm, then a chance of showers and thunderstorms, mainly after 5pm. Patchy fog before 8am. Otherwise, mostly cloudy, with a high near 83. Light south wind increasing to 5 to 10 mph in the morning. Chance of precipitation is 30%.

    High: 83 °F

    Patchy
    Drizzle 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 74. Southwest wind 5 to 10 mph. Chance of precipitation is 60%. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

    Low: 74 °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 86. South wind 3 to 8 mph. Chance of precipitation is 60%. New rainfall amounts between a quarter and half of an inch possible.

    High: 86 °F

    Showers
    Likely

  • Tuesday Night

    Tuesday Night: A slight chance of showers before 8pm, then a slight chance of showers and thunderstorms after 2am. Mostly cloudy, with a low around 75. Southwest wind 5 to 7 mph. Chance of precipitation is 20%.

    Low: 75 °F

    Partly Cloudy
    then Slight
    Chance
    T-storms

  • Wednesday

    Wednesday: A 20 percent chance of showers and thunderstorms. Partly sunny, with a high near 88. South wind 5 to 13 mph.

    High: 88 °F

    Slight Chance
    T-storms

  • Wednesday Night

    Wednesday Night: A 30 percent chance of showers. Mostly cloudy, with a low around 76.

    Low: 76 °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 77.

    Low: 77 °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 91.

    High: 91 °F

    Mostly Sunny
    then Chance
    T-storms

Detailed Forecast

Today
Patchy drizzle before 2pm, then a chance of showers and thunderstorms, mainly after 5pm. Patchy fog before 8am. Otherwise, mostly cloudy, with a high near 83. Light south wind increasing to 5 to 10 mph in the morning. Chance of precipitation is 30%.
Tonight
A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 2am. Mostly cloudy, with a low around 74. Southwest wind 5 to 10 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 86. South wind 3 to 8 mph. Chance of precipitation is 60%. New rainfall amounts between a quarter and half of an inch possible.
Tuesday Night
A slight chance of showers before 8pm, then a slight chance of showers and thunderstorms after 2am. Mostly cloudy, with a low around 75. Southwest wind 5 to 7 mph. Chance of precipitation is 20%.
Wednesday
A 20 percent chance of showers and thunderstorms. Partly sunny, with a high near 88. South wind 5 to 13 mph.
Wednesday Night
A 30 percent chance of showers. Mostly cloudy, with a low around 76.
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 77.
Friday
A 40 percent chance of showers and thunderstorms after 2pm. Mostly sunny, with a high near 91.
Friday Night
A 30 percent chance of showers and thunderstorms before 8pm. Mostly cloudy, with a low around 74.
Saturday
Mostly sunny, with a high near 87.
Saturday Night
Partly cloudy, with a low around 73.
Sunday
A 30 percent chance of showers. Mostly sunny, with a high near 86.
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ABOUT THIS FORECAST

 
Point Forecast:
Islip, Long Island Mac Arthur Airport NY
 40.81°N 73.11°W (Elev. 98 ft)
Last Update:
2:18 am EDT Jul 14, 2025
Forecast Valid:
6am EDT Jul 14, 2025-6pm EDT Jul 20, 2025
 
Forecast Discussion
 
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Additional Resources

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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