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.

Partly Cloudy

79°F

26°C

Humidity 77%
Wind Speed SW 7 mph
Barometer 29.98 in (1015.1 mb)
Dewpoint 71°F (22°C)
Visibility 10.00 mi
Heat Index82°F (28°C)
Last update 28 Jun 6:56 pm EDT
Extended Forecast for

Sayville NY

  • Tonight

    Tonight: A 50 percent chance of showers and thunderstorms after 8pm. Areas of fog between 8pm and 2am. Otherwise, mostly cloudy, with a low around 70. Southwest wind 6 to 8 mph.

    Low: 70 °F

    Chance
    T-storms and
    Areas Fog

  • Sunday

    Sunday: Mostly sunny, with a high near 85. West wind 6 to 8 mph.

    High: 85 °F

    Mostly Sunny

  • Sunday Night

    Sunday Night: Partly cloudy, with a low around 69. Southwest wind around 6 mph becoming calm in the evening.

    Low: 69 °F

    Partly Cloudy

  • Monday

    Monday: Mostly sunny, with a high near 83. Calm wind becoming south 5 to 8 mph in the afternoon.

    High: 83 °F

    Mostly Sunny

  • Monday Night

    Monday Night: A 30 percent chance of showers and thunderstorms, mainly after 2am. Mostly cloudy, with a low around 71. Southwest wind around 8 mph.

    Low: 71 °F

    Slight Chance
    T-storms then
    Chance
    Showers

  • Tuesday

    Tuesday: A chance of showers before 8am, then showers likely and possibly a thunderstorm after 2pm. Partly sunny, with a high near 83. Chance of precipitation is 70%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

    High: 83 °F

    Chance
    Showers then
    Showers
    Likely

  • Tuesday Night

    Tuesday Night: Showers likely and possibly a thunderstorm before 8pm, then a chance of showers between 8pm and 2am. Mostly cloudy, with a low around 70. Chance of precipitation is 60%.

    Low: 70 °F

    Showers
    Likely

  • Wednesday

    Wednesday: Mostly sunny, with a high near 83.

    High: 83 °F

    Mostly Sunny

  • Wednesday Night

    Wednesday Night: Mostly clear, with a low around 70.

    Low: 70 °F

    Mostly Clear

Detailed Forecast

Tonight
A 50 percent chance of showers and thunderstorms after 8pm. Areas of fog between 8pm and 2am. Otherwise, mostly cloudy, with a low around 70. Southwest wind 6 to 8 mph.
Sunday
Mostly sunny, with a high near 85. West wind 6 to 8 mph.
Sunday Night
Partly cloudy, with a low around 69. Southwest wind around 6 mph becoming calm in the evening.
Monday
Mostly sunny, with a high near 83. Calm wind becoming south 5 to 8 mph in the afternoon.
Monday Night
A 30 percent chance of showers and thunderstorms, mainly after 2am. Mostly cloudy, with a low around 71. Southwest wind around 8 mph.
Tuesday
A chance of showers before 8am, then showers likely and possibly a thunderstorm after 2pm. Partly sunny, with a high near 83. Chance of precipitation is 70%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Tuesday Night
Showers likely and possibly a thunderstorm before 8pm, then a chance of showers between 8pm and 2am. Mostly cloudy, with a low around 70. Chance of precipitation is 60%.
Wednesday
Mostly sunny, with a high near 83.
Wednesday Night
Mostly clear, with a low around 70.
Thursday
Sunny, with a high near 84.
Thursday Night
Partly cloudy, with a low around 68.
Independence Day
Sunny, with a high near 81.
Friday Night
Partly cloudy, with a low around 67.
Saturday
Mostly sunny, with a high near 81.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Sayville NY
 40.73°N 73.07°W (Elev. 16 ft)
Last Update:
5:34 pm EDT Jun 28, 2025
Forecast Valid:
7pm EDT Jun 28, 2025-6pm EDT Jul 5, 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