Current conditions at
Islip, Long Island Mac Arthur Airport (KISP)
Lat: 40.79°NLon: 73.1°WElev: 98ft.
Fog/Mist
40°F
4°C
| Humidity | 97% |
| Wind Speed | E 3 mph |
| Barometer | 30.35 in (1027.9 mb) |
| Dewpoint | 39°F (4°C) |
| Visibility | 2.00 mi |
| Last update | 3 Apr 4:56 am EDT |
Extended Forecast for
Port Jefferson NY
Today
High: 60 °F
Patchy Fog
then Partly
SunnyTonight
Low: 50 °F
Mostly Cloudy
then Patchy
FogSaturday
High: 64 °F
Patchy Fog
then Slight
Chance
ShowersSaturday Night

Low: 42 °F
Chance
ShowersSunday

High: 60 °F
Showers
Sunday Night

Low: 39 °F
Decreasing
CloudsMonday

High: 52 °F
Mostly Sunny
Monday Night

Low: 38 °F
Partly Cloudy
Tuesday

High: 50 °F
Partly Sunny
Detailed Forecast
Today
Patchy fog before 11am. Otherwise, cloudy, then gradually becoming mostly sunny, with a high near 60. Calm wind becoming southwest 5 to 8 mph in the afternoon.
Tonight
Patchy fog after 2am. Otherwise, mostly cloudy, with a low around 50. Southwest wind 7 to 10 mph.
Saturday
A 20 percent chance of showers after 2pm. Patchy fog before 8am. Otherwise, partly sunny, with a high near 64. Light and variable wind becoming east 5 to 8 mph in the afternoon.
Saturday Night
A 50 percent chance of showers, mainly after 8pm. Mostly cloudy, with a low around 42. East wind 7 to 11 mph, with gusts as high as 21 mph.
Sunday
Showers. High near 60. South wind 10 to 14 mph. Chance of precipitation is 100%. New precipitation amounts between a quarter and half of an inch possible.
Sunday Night
Cloudy, then gradually becoming partly cloudy, with a low around 39.
Monday
Mostly sunny, with a high near 52.
Monday Night
Partly cloudy, with a low around 38.
Tuesday
Partly sunny, with a high near 50.
Tuesday Night
Mostly clear, with a low around 31.
Wednesday
Sunny, with a high near 48.
Wednesday Night
Mostly clear, with a low around 36.
Thursday
Sunny, with a high near 55.
Additional Forecasts and Information
Basemap Options
Click map to change the forecast location
Loading map...
ABOUT THIS FORECAST
Point Forecast:
Port Jefferson NY
40.93°N 73.06°W (Elev. 161 ft)
40.93°N 73.06°W (Elev. 161 ft)
2:20 am EDT Apr 3, 2026
5am EDT Apr 3, 2026-6pm EDT Apr 9, 2026


