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

60°F

16°C

Humidity 65%
Wind Speed N 3 mph
Barometer 30.43 in (1030.2 mb)
Dewpoint 48°F (9°C)
Visibility 10.00 mi
Last update 10 Oct 8:56 am EDT
Extended Forecast for

Mount Sinai NY

  • Today

    Today: Partly sunny, with a high near 64. Northeast wind 3 to 7 mph.

    High: 64 °F

    Partly Sunny

  • Tonight

    Tonight: Mostly cloudy, with a low around 51. Southeast wind 3 to 5 mph.

    Low: 51 °F

    Mostly Cloudy

  • Sunday

    Sunday: Rain likely, mainly after 2pm. Cloudy, with a high near 65. Southeast wind 7 to 10 mph. Chance of precipitation is 70%. New precipitation amounts between a quarter and half of an inch possible.

    High: 65 °F

    Slight Chance
    Rain then
    Rain Likely

  • Sunday Night

    Sunday Night: Rain, with thunderstorms also possible after 11pm. Low around 58. East wind 9 to 14 mph. Chance of precipitation is 100%. New rainfall amounts between a half and three quarters of an inch possible.

    Low: 58 °F

    Rain

  • Columbus Day

    Columbus Day: Rain likely, mainly before 8am. Cloudy, then gradually becoming mostly sunny, with a high near 67. North wind 9 to 11 mph. Chance of precipitation is 60%. New precipitation amounts of less than a tenth of an inch possible.

    High: 67 °F

    Rain Likely

  • Monday Night

    Monday Night: Mostly clear, with a low around 56.

    Low: 56 °F

    Mostly Clear

  • Tuesday

    Tuesday: A 30 percent chance of showers after 2pm. Partly sunny, with a high near 68.

    High: 68 °F

    Mostly Sunny
    then Chance
    Showers

  • Tuesday Night

    Tuesday Night: Showers likely, mainly between 8pm and 2am. Mostly cloudy, with a low around 54. Chance of precipitation is 60%.

    Low: 54 °F

    Showers
    Likely

  • Wednesday

    Wednesday: A 30 percent chance of showers before 8am. Partly sunny, with a high near 63.

    High: 63 °F

    Chance
    Showers then
    Mostly Sunny

Detailed Forecast

Today
Partly sunny, with a high near 64. Northeast wind 3 to 7 mph.
Tonight
Mostly cloudy, with a low around 51. Southeast wind 3 to 5 mph.
Sunday
Rain likely, mainly after 2pm. Cloudy, with a high near 65. Southeast wind 7 to 10 mph. Chance of precipitation is 70%. New precipitation amounts between a quarter and half of an inch possible.
Sunday Night
Rain, with thunderstorms also possible after 11pm. Low around 58. East wind 9 to 14 mph. Chance of precipitation is 100%. New rainfall amounts between a half and three quarters of an inch possible.
Columbus Day
Rain likely, mainly before 8am. Cloudy, then gradually becoming mostly sunny, with a high near 67. North wind 9 to 11 mph. Chance of precipitation is 60%. New precipitation amounts of less than a tenth of an inch possible.
Monday Night
Mostly clear, with a low around 56.
Tuesday
A 30 percent chance of showers after 2pm. Partly sunny, with a high near 68.
Tuesday Night
Showers likely, mainly between 8pm and 2am. Mostly cloudy, with a low around 54. Chance of precipitation is 60%.
Wednesday
A 30 percent chance of showers before 8am. Partly sunny, with a high near 63.
Wednesday Night
Mostly clear, with a low around 48.
Thursday
Sunny, with a high near 60.
Thursday Night
Partly cloudy, with a low around 50.
Friday
A 40 percent chance of showers. Partly sunny, with a high near 62.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Mount Sinai NY
 40.93°N 73.03°W (Elev. 151 ft)
Last Update:
2:11 am EDT Oct 10, 2026
Forecast Valid:
9am EDT Oct 10, 2026-6pm EDT Oct 16, 2026
 
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