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

58°F

14°C

Humidity 78%
Wind Speed SE 6 mph
Barometer 30.11 in (1019.6 mb)
Dewpoint 51°F (11°C)
Visibility 10.00 mi
Last update 16 Oct 12:56 am EDT
Extended Forecast for

Mount Sinai NY

  • Overnight

    Overnight: A 30 percent chance of showers after 5am. Mostly cloudy, with a low around 52. Southeast wind 6 to 8 mph.

    Low: 52 °F

    Chance
    Showers

  • Friday

    Friday: Showers, with thunderstorms also possible after 2pm. High near 71. Southwest wind 10 to 13 mph, with gusts as high as 23 mph. Chance of precipitation is 90%. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

    High: 71 °F

    Showers then
    Chance
    Showers

  • Friday Night

    Friday Night: A chance of showers and thunderstorms, then showers after 8pm. Low around 46. West wind 10 to 15 mph becoming northwest after midnight. Chance of precipitation is 90%. New precipitation amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

    Low: 46 °F

    Showers then
    Showers
    Likely

  • Saturday

    Saturday: Cloudy through mid morning, then gradual clearing, with a steady temperature around 50. North wind 16 to 18 mph.

    High: 50 °F

    Gradual
    Clearing

  • Saturday Night

    Saturday Night: Mostly clear, with a low around 41. North wind 11 to 16 mph.

    Low: 41 °F

    Mostly Clear

  • Sunday

    Sunday: Sunny, with a high near 56.

    High: 56 °F

    Sunny

  • Sunday Night

    Sunday Night: Mostly clear, with a low around 47.

    Low: 47 °F

    Mostly Clear

  • Monday

    Monday: Sunny, with a high near 60.

    High: 60 °F

    Sunny

  • Monday Night

    Monday Night: Partly cloudy, with a low around 50.

    Low: 50 °F

    Partly Cloudy

Detailed Forecast

Overnight
A 30 percent chance of showers after 5am. Mostly cloudy, with a low around 52. Southeast wind 6 to 8 mph.
Friday
Showers, with thunderstorms also possible after 2pm. High near 71. Southwest wind 10 to 13 mph, with gusts as high as 23 mph. Chance of precipitation is 90%. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.
Friday Night
A chance of showers and thunderstorms, then showers after 8pm. Low around 46. West wind 10 to 15 mph becoming northwest after midnight. Chance of precipitation is 90%. New precipitation amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Saturday
Cloudy through mid morning, then gradual clearing, with a steady temperature around 50. North wind 16 to 18 mph.
Saturday Night
Mostly clear, with a low around 41. North wind 11 to 16 mph.
Sunday
Sunny, with a high near 56.
Sunday Night
Mostly clear, with a low around 47.
Monday
Sunny, with a high near 60.
Monday Night
Partly cloudy, with a low around 50.
Tuesday
Mostly sunny, with a high near 63.
Tuesday Night
Partly cloudy, with a low around 52.
Wednesday
Sunny, with a high near 63.
Wednesday Night
Mostly clear, with a low around 50.
Thursday
Mostly sunny, with a high near 60.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Mount Sinai NY
 40.95°N 73.02°W (Elev. 56 ft)
Last Update:
2:36 pm EDT Oct 15, 2026
Forecast Valid:
1am EDT Oct 16, 2026-6pm EDT Oct 22, 2026
 
Forecast Discussion
 
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Additional Resources

Radar & Satellite Image

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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