Current conditions at
Islip, Long Island Mac Arthur Airport (KISP)
Lat: 40.79°NLon: 73.1°WElev: 98ft.
Mostly Cloudy
44°F
7°C
| Humidity | 68% |
| Wind Speed | NE 7 mph |
| Barometer | 30.25 in (1024.3 mb) |
| Dewpoint | 34°F (1°C) |
| Visibility | 10.00 mi |
| Wind Chill | 40°F (4°C) |
| Last update | 4 Mar 12:56 pm EST |
Extended Forecast for
Port Jefferson NY
This Afternoon

High: 40 °F
Mostly Sunny
Tonight
Low: 32 °F
Patchy Fog
then Chance
Rain and
Patchy FogThursday

High: 38 °F
Rain and
Patchy FogThursday Night

Low: 38 °F
Rain and
BreezyFriday

High: 40 °F
Chance Rain
Friday Night

Low: 36 °F
Cloudy
Saturday

High: 48 °F
Cloudy
Saturday Night

Low: 43 °F
Showers
LikelySunday

High: 50 °F
Partly Sunny
Detailed Forecast
This Afternoon
Mostly sunny, with a high near 40. Calm wind.
Tonight
A 30 percent chance of rain after 4am. Patchy fog after 10pm. Otherwise, increasing clouds, with a low around 32. Calm wind.
Thursday
Rain, mainly after 7am. Patchy fog before 1pm. High near 38. Light northeast wind becoming east 6 to 11 mph in the morning. Chance of precipitation is 90%. New precipitation amounts between a quarter and half of an inch possible.
Thursday Night
Rain. Steady temperature around 38. Breezy, with a northeast wind 16 to 20 mph. Chance of precipitation is 100%. New precipitation amounts between a half and three quarters of an inch possible.
Friday
A 30 percent chance of rain before 1pm. Cloudy, with a high near 40. Northeast wind 9 to 16 mph.
Friday Night
Cloudy, with a low around 36.
Saturday
Cloudy, with a high near 48.
Saturday Night
Showers likely, mainly before 1am. Cloudy, with a low around 43. Chance of precipitation is 60%.
Sunday
Partly sunny, with a high near 50.
Sunday Night
Partly cloudy, with a low around 42.
Monday
Mostly sunny, with a high near 50.
Monday Night
Partly cloudy, with a low around 44.
Tuesday
Mostly sunny, with a high near 55.
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)
1:01 pm EST Mar 4, 2026
1pm EST Mar 4, 2026-6pm EDT Mar 10, 2026


