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.

Overcast

37°F

3°C

Humidity 89%
Wind Speed NE 7 mph
Barometer 30.11 in (1019.6 mb)
Dewpoint 34°F (1°C)
Visibility 10.00 mi
Wind Chill32°F (0°C)
Last update 22 Feb 12:56 am EST
Extended Forecast for

Port Jefferson NY

Blizzard Warning February 22, 01:00pm until February 23, 06:00pm
Coastal Flood Warning February 23, 12:00am until February 23, 05:00am
Click here for hazard details and duration
Blizzard Warning
Coastal Flood Warning

  • Overnight

    Overnight: A 40 percent chance of snow. Cloudy, with a low around 30. Wind chill values between 25 and 30. East wind 10 to 13 mph.

    Low: 30 °F

    Chance Snow

  • Sunday

    Sunday: Snow likely, mainly after 1pm. Cloudy, with a high near 38. Wind chill values between 20 and 30. Breezy, with an east wind 15 to 22 mph. Chance of precipitation is 70%. New snow accumulation of less than one inch possible.

    High: 38 °F

    Chance Snow
    then Snow
    Likely and
    Breezy

  • Sunday Night

    Sunday Night: Snow. The snow could be heavy at times. Areas of blowing snow after 10pm. Low around 31. Wind chill values between 15 and 20. Very windy, with a north wind 25 to 30 mph increasing to 35 to 40 mph after midnight. Chance of precipitation is 100%. New snow accumulation of 10 to 14 inches possible.

    Low: 31 °F

    Heavy Snow
    and Areas
    Blowing Snow

  • Monday

    Monday: Snow. The snow could be heavy at times. Areas of blowing snow. Steady temperature around 30. Wind chill values between 10 and 15. Windy, with a north wind 31 to 39 mph, with gusts as high as 55 mph. Chance of precipitation is 100%. New snow accumulation of 4 to 8 inches possible.

    High: 30 °F

    Heavy Snow
    and Areas
    Blowing Snow

  • Monday Night

    Monday Night: A 40 percent chance of snow before 10pm. Areas of blowing snow before 1am. Mostly cloudy, with a low around 25. Windy, with a northwest wind 17 to 26 mph.

    Low: 25 °F

    Chance Snow
    and Areas
    Blowing Snow

  • Tuesday

    Tuesday: Mostly sunny, with a steady temperature around 27.

    High: 27 °F

    Mostly Sunny

  • Tuesday Night

    Tuesday Night: Increasing clouds, with a low around 22.

    Low: 22 °F

    Increasing
    Clouds

  • Wednesday

    Wednesday: A chance of rain and snow before 1pm, then a chance of rain. Mostly cloudy, with a high near 37. Chance of precipitation is 50%.

    High: 37 °F

    Chance
    Rain/Snow

  • Wednesday Night

    Wednesday Night: A 30 percent chance of rain. Mostly cloudy, with a low around 33.

    Low: 33 °F

    Chance Rain

Detailed Forecast

Overnight
A 40 percent chance of snow. Cloudy, with a low around 30. Wind chill values between 25 and 30. East wind 10 to 13 mph.
Sunday
Snow likely, mainly after 1pm. Cloudy, with a high near 38. Wind chill values between 20 and 30. Breezy, with an east wind 15 to 22 mph. Chance of precipitation is 70%. New snow accumulation of less than one inch possible.
Sunday Night
Snow. The snow could be heavy at times. Areas of blowing snow after 10pm. Low around 31. Wind chill values between 15 and 20. Very windy, with a north wind 25 to 30 mph increasing to 35 to 40 mph after midnight. Chance of precipitation is 100%. New snow accumulation of 10 to 14 inches possible.
Monday
Snow. The snow could be heavy at times. Areas of blowing snow. Steady temperature around 30. Wind chill values between 10 and 15. Windy, with a north wind 31 to 39 mph, with gusts as high as 55 mph. Chance of precipitation is 100%. New snow accumulation of 4 to 8 inches possible.
Monday Night
A 40 percent chance of snow before 10pm. Areas of blowing snow before 1am. Mostly cloudy, with a low around 25. Windy, with a northwest wind 17 to 26 mph.
Tuesday
Mostly sunny, with a steady temperature around 27.
Tuesday Night
Increasing clouds, with a low around 22.
Wednesday
A chance of rain and snow before 1pm, then a chance of rain. Mostly cloudy, with a high near 37. Chance of precipitation is 50%.
Wednesday Night
A 30 percent chance of rain. Mostly cloudy, with a low around 33.
Thursday
A 40 percent chance of rain. Partly sunny, with a high near 40.
Thursday Night
A 50 percent chance of rain. Mostly cloudy, with a low around 33.
Friday
A 40 percent chance of rain. Partly sunny, with a high near 39.
Friday Night
Partly cloudy, with a low around 30.
Saturday
Mostly sunny, with a high near 41.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Port Jefferson NY
 40.96°N 73.08°W (Elev. 3 ft)
Last Update:
3:48 pm EST Feb 21, 2026
Forecast Valid:
1am EST Feb 22, 2026-6pm EST Feb 28, 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