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.

Snow Freezing Fog and Windy

30°F

-1°C

Humidity 92%
Wind Speed N 29 G 41 mph
Barometer 29.46 in (997.5 mb)
Dewpoint 28°F (-2°C)
Visibility 0.50 mi
Wind Chill15°F (-9°C)
Last update 23 Feb 1:56 am EST
Extended Forecast for

Mount Sinai NY

Blizzard Warning February 23, 02:21am until February 23, 06:00pm
Coastal Flood Warning until February 23, 05:00am
Click here for hazard details and duration
Blizzard Warning
Coastal Flood Warning
  •  
    Blizzard Warning February 23, 02:21am until February 23, 06:00pm
    Coastal Flood Warning until February 23, 05:00am

    NOW: Multiple hazards in effect

    Click HERE for Details

  • Overnight

    Low: 29 °F

    Heavy Snow
    and Areas
    Blowing Snow

  • Monday

    Monday: Snow, mainly before 4pm. The snow could be heavy at times. Areas of blowing snow. High near 33. Wind chill values between 10 and 20. Windy, with a north wind 32 to 37 mph decreasing to 25 to 30 mph in the afternoon. Winds could gust as high as 55 mph. Chance of precipitation is 100%. New snow accumulation of 3 to 7 inches possible.

    High: 33 °F

    Heavy Snow
    and Areas
    Blowing Snow

  • Monday Night

    Monday Night: A 30 percent chance of snow before 7pm. Mostly cloudy, with a low around 21. Wind chill values between 10 and 15. Blustery, with a northwest wind 14 to 22 mph, with gusts as high as 34 mph.

    Low: 21 °F

    Chance Snow
    and Blustery
    then Mostly
    Cloudy

  • Tuesday

    Tuesday: Mostly sunny, with a high near 30. Wind chill values between 10 and 20. West wind 8 to 11 mph.

    High: 30 °F

    Mostly Sunny

  • Tuesday Night

    Tuesday Night: A 50 percent chance of snow, mainly after 4am. Mostly cloudy, with a low around 19. West wind around 6 mph becoming calm.

    Low: 19 °F

    Partly Cloudy
    then Chance
    Snow

  • Wednesday

    Wednesday: Rain and snow likely, becoming all rain after 10am, then gradually ending. Cloudy, then gradually becoming mostly sunny, with a high near 39. Chance of precipitation is 70%. New snow accumulation of less than a half inch possible.

    High: 39 °F

    Rain/Snow
    Likely then
    Rain Likely

  • Wednesday Night

    Wednesday Night: Partly cloudy, with a low around 27.

    Low: 27 °F

    Partly Cloudy

  • Thursday

    Thursday: A chance of rain and snow after 1pm. Partly sunny, with a high near 39. Chance of precipitation is 50%.

    High: 39 °F

    Partly Sunny
    then Chance
    Rain/Snow

Detailed Forecast

Overnight
Snow. The snow could be heavy at times. Areas of blowing snow. Low around 29. Wind chill values between 10 and 15. Windy, with a north wind 33 to 36 mph, with gusts as high as 50 mph. Chance of precipitation is 100%. Total nighttime snow accumulation of 12 to 18 inches possible.
Monday
Snow, mainly before 4pm. The snow could be heavy at times. Areas of blowing snow. High near 33. Wind chill values between 10 and 20. Windy, with a north wind 32 to 37 mph decreasing to 25 to 30 mph in the afternoon. Winds could gust as high as 55 mph. Chance of precipitation is 100%. New snow accumulation of 3 to 7 inches possible.
Monday Night
A 30 percent chance of snow before 7pm. Mostly cloudy, with a low around 21. Wind chill values between 10 and 15. Blustery, with a northwest wind 14 to 22 mph, with gusts as high as 34 mph.
Tuesday
Mostly sunny, with a high near 30. Wind chill values between 10 and 20. West wind 8 to 11 mph.
Tuesday Night
A 50 percent chance of snow, mainly after 4am. Mostly cloudy, with a low around 19. West wind around 6 mph becoming calm.
Wednesday
Rain and snow likely, becoming all rain after 10am, then gradually ending. Cloudy, then gradually becoming mostly sunny, with a high near 39. Chance of precipitation is 70%. New snow accumulation of less than a half inch possible.
Wednesday Night
Partly cloudy, with a low around 27.
Thursday
A chance of rain and snow after 1pm. Partly sunny, with a high near 39. Chance of precipitation is 50%.
Thursday Night
Rain likely. Mostly cloudy, with a low around 30. Chance of precipitation is 70%.
Friday
Partly sunny, with a high near 41.
Friday Night
Mostly clear, with a low around 27.
Saturday
Sunny, with a high near 42.
Saturday Night
Partly cloudy, with a low around 30.
Sunday
Partly sunny, with a high near 42.
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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:
1:42 am EST Feb 23, 2026
Forecast Valid:
2am EST Feb 23, 2026-6pm EST Mar 1, 2026
 
Forecast Discussion
 
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Additional Resources

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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