National Oceanic and Atmospheric Administration National Weather Service United States Department of Commerce

Hazardous Weather Conditions

Current conditions at

Islip, Long Island Mac Arthur Airport (KISP)

Lat: 40.79°NLon: 73.1°WElev: 98ft.

Partly Cloudy

26°C

78°F

Humidity 85%
Wind Speed S 15 km/h
Barometer 1017.3 mb (30.05 in)
Dewpoint 23°C (73°F)
Visibility 16 km
Heat Index27°C (80°F)
Last update 15 Jul 4:56 pm EDT
Extended Forecast for

Sayville NY

Heat Advisory July 16, 11:00am until July 17, 10:00pm
Click here for hazard details and duration
Heat Advisory

  • Tonight

    Tonight: Patchy fog after 11pm. Otherwise, partly cloudy, with a low around 23. South wind 5 to 10 km/h becoming calm in the evening.

    Low: 23 °C

    Patchy Fog

  • Wednesday

    Wednesday: Mostly sunny, with a high near 28. Light southwest wind becoming south 9 to 14 km/h in the morning.

    High: 28 °C

    Mostly Sunny

  • Wednesday Night

    Wednesday Night: A 50 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 23. Southwest wind 11 to 13 km/h.

    Low: 23 °C

    Chance
    T-storms

  • Thursday

    Thursday: A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 2pm. Partly sunny, with a high near 29. Southwest wind 13 to 21 km/h. Chance of precipitation is 60%. New rainfall amounts between 1 and 2.5 mm, except higher amounts possible in thunderstorms.

    High: 29 °C

    Showers
    Likely

  • Thursday Night

    Thursday Night: Showers likely and possibly a thunderstorm before 8pm. Partly cloudy, with a low around 24. Southwest wind 13 to 16 km/h. Chance of precipitation is 60%.

    Low: 24 °C

    Showers
    Likely then
    Partly Cloudy

  • Friday

    Friday: Mostly sunny, with a high near 30.

    High: 30 °C

    Mostly Sunny

  • Friday Night

    Friday Night: Partly cloudy, with a low around 21.

    Low: 21 °C

    Partly Cloudy

  • Saturday

    Saturday: Sunny, with a high near 27.

    High: 27 °C

    Sunny

  • Saturday Night

    Saturday Night: Mostly cloudy, with a low around 22.

    Low: 22 °C

    Mostly Cloudy

Detailed Forecast

Tonight
Patchy fog after 11pm. Otherwise, partly cloudy, with a low around 23. South wind 5 to 10 km/h becoming calm in the evening.
Wednesday
Mostly sunny, with a high near 28. Light southwest wind becoming south 9 to 14 km/h in the morning.
Wednesday Night
A 50 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 23. Southwest wind 11 to 13 km/h.
Thursday
A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 2pm. Partly sunny, with a high near 29. Southwest wind 13 to 21 km/h. Chance of precipitation is 60%. New rainfall amounts between 1 and 2.5 mm, except higher amounts possible in thunderstorms.
Thursday Night
Showers likely and possibly a thunderstorm before 8pm. Partly cloudy, with a low around 24. Southwest wind 13 to 16 km/h. Chance of precipitation is 60%.
Friday
Mostly sunny, with a high near 30.
Friday Night
Partly cloudy, with a low around 21.
Saturday
Sunny, with a high near 27.
Saturday Night
Mostly cloudy, with a low around 22.
Sunday
A 40 percent chance of showers after 8am. Partly sunny, with a high near 27.
Sunday Night
A 30 percent chance of showers. Mostly cloudy, with a low around 22.
Monday
Mostly sunny, with a high near 28.
Monday Night
Partly cloudy, with a low around 21.
Tuesday
Mostly sunny, with a high near 27.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Sayville NY
 40.73°N 73.07°W (Elev. 16 m)
Last Update:
3:16 pm EDT Jul 15, 2025
Forecast Valid:
5pm EDT Jul 15, 2025-6pm EDT Jul 22, 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