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

76°F

24°C

Humidity 88%
Wind Speed SE 5 mph
Barometer 30.07 in (1018.0 mb)
Dewpoint 72°F (22°C)
Visibility 10.00 mi
Heat Index76°F (24°C)
Last update 14 Jul 2:56 am EDT
Extended Forecast for

Islip, Long Island Mac Arthur Airport NY

  • Overnight

    Overnight: Patchy drizzle after 5am. Patchy fog. Otherwise, mostly cloudy, with a low around 71. Calm wind.

    Low: 71 °F

    Patchy
    Drizzle and
    Patchy Fog

  • Monday

    Monday: 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 9 mph in the morning. Chance of precipitation is 30%.

    High: 83 °F

    Patchy
    Drizzle and
    Patchy Fog
    then Chance
    T-storms

  • Monday Night

    Monday Night: 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 8 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 around 6 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 slight chance of showers before 8pm, then a slight chance of showers and thunderstorms after 2am. Mostly cloudy, with a low around 73. Southwest wind 3 to 6 mph. Chance of precipitation is 20%.

    Low: 73 °F

    Partly Cloudy
    then Slight
    Chance
    T-storms

  • Wednesday

    Wednesday: Partly sunny, with a high near 87.

    High: 87 °F

    Partly Sunny

  • 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 89.

    High: 89 °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

Detailed Forecast

Overnight
Patchy drizzle after 5am. Patchy fog. Otherwise, mostly cloudy, with a low around 71. Calm wind.
Monday
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 9 mph in the morning. Chance of precipitation is 30%.
Monday Night
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 8 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 around 6 mph in the afternoon. 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 73. Southwest wind 3 to 6 mph. Chance of precipitation is 20%.
Wednesday
Partly sunny, with a high near 87.
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 89.
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 91.
Friday Night
A 30 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 72.
Saturday
Mostly sunny, with a high near 87.
Saturday Night
Partly cloudy, with a low around 71.
Sunday
A 30 percent chance of showers. Mostly sunny, with a high near 85.
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ABOUT THIS FORECAST

 
Point Forecast:
Islip, Long Island Mac Arthur Airport NY
 40.8°N 73.09°W (Elev. 98 ft)
Last Update:
2:18 am EDT Jul 14, 2025
Forecast Valid:
3am EDT Jul 14, 2025-6pm EDT Jul 20, 2025
 
Forecast Discussion
 
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Additional Resources

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National Digital Forecast Database

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High Temperature

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Chance of Precipitation