Current conditions at
Islip, Long Island Mac Arthur Airport (KISP)
Lat: 40.79°NLon: 73.1°WElev: 98ft.
Fog/Mist
33°F
1°C
| Humidity | 96% |
| Wind Speed | Calm |
| Barometer | 30.03 in (1016.9 mb) |
| Dewpoint | 32°F (0°C) |
| Visibility | 4.00 mi |
| Last update | 28 Feb 10:56 pm EST |
Extended Forecast for
Port Jefferson NY
Tonight

Low: 27 °F
Areas Fog
Sunday

High: 34 °F
Snow Likely
Sunday Night

Low: 15 °F
Mostly Clear
Monday

High: 28 °F
Sunny
Monday Night

Low: 19 °F
Mostly Clear
Tuesday
High: 40 °F
Chance
Rain/Snow
then
Rain/Snow
LikelyTuesday Night

Low: 38 °F
Rain
Wednesday

High: 44 °F
Mostly Cloudy
Wednesday Night

Low: 37 °F
Chance Rain
Detailed Forecast
Tonight
Areas of fog before 2am. Otherwise, cloudy, then gradually becoming partly cloudy, with a low around 27. Calm wind becoming north 5 to 7 mph after midnight.
Sunday
Snow likely, mainly before 1pm. Cloudy, with a high near 34. Wind chill values between 15 and 25. North wind 8 to 13 mph. Chance of precipitation is 60%. New snow accumulation of less than one inch possible.
Sunday Night
Mostly clear, with a low around 15. Wind chill values between zero and 10. North wind 14 to 16 mph.
Monday
Sunny, with a high near 28. Wind chill values between zero and 10. North wind 5 to 13 mph becoming west in the afternoon.
Monday Night
Mostly clear, with a low around 19. South wind 3 to 6 mph.
Tuesday
A chance of rain and snow before 1pm, then rain likely. Mostly cloudy, with a high near 40. Chance of precipitation is 70%. Little or no snow accumulation expected.
Tuesday Night
Rain. Low around 38. Chance of precipitation is 90%.
Wednesday
Mostly cloudy, with a high near 44.
Wednesday Night
A 40 percent chance of rain. Cloudy, with a low around 37.
Thursday
A 40 percent chance of rain. Cloudy, with a high near 48.
Thursday Night
A 50 percent chance of rain. Cloudy, with a low around 40.
Friday
A 40 percent chance of rain. Cloudy, with a high near 45.
Friday Night
A 30 percent chance of rain. Cloudy, with a low around 40.
Saturday
Mostly cloudy, with a high near 50.
Additional Forecasts and Information
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ABOUT THIS FORECAST
Point Forecast:
Port Jefferson NY
40.96°N 73.08°W (Elev. 3 ft)
40.96°N 73.08°W (Elev. 3 ft)
11:34 pm EST Feb 28, 2026
11pm EST Feb 28, 2026-6pm EST Mar 7, 2026


