National Oceanic and Atmospheric Administration National Weather Service United States Department of Commerce
Current conditions at

Trenton-Mercer Airport (KTTN)

Lat: 40.28°NLon: 74.82°WElev: 210ft.

Overcast

74°F

23°C

Humidity 85%
Wind Speed SE 5 mph
Barometer 30.08 in (1017.8 mb)
Dewpoint 69°F (21°C)
Visibility 10.00 mi
Last update 13 Jul 12:53 am EDT
Extended Forecast for

Princeton Junction NJ

  • Overnight

    Overnight: Cloudy, with a low around 69. East wind around 5 mph.

    Low: 69 °F

    Cloudy

  • Sunday

    Sunday: Patchy fog before 7am. Otherwise, mostly cloudy, with a high near 86. Southeast wind 5 to 10 mph.

    High: 86 °F

    Patchy Fog
    then Partly
    Sunny

  • Sunday Night

    Sunday Night: A slight chance of showers and thunderstorms, mainly between 10pm and 11pm. Patchy fog after midnight. Otherwise, mostly cloudy, with a low around 70. Southeast wind 5 to 10 mph becoming light and variable after midnight. Chance of precipitation is 20%.

    Low: 70 °F

    Slight Chance
    T-storms then
    Patchy Fog

  • Monday

    Monday: A chance of showers, then showers likely and possibly a thunderstorm after 2pm. Patchy fog before 9am. Otherwise, mostly cloudy, with a high near 87. South wind around 5 mph. Chance of precipitation is 70%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

    High: 87 °F

    Chance
    Showers and
    Patchy Fog
    then Showers
    Likely

  • Monday Night

    Monday Night: Showers likely and possibly a thunderstorm before 8pm, then a chance of showers and thunderstorms between 8pm and 2am. Mostly cloudy, with a low around 70. Calm wind. Chance of precipitation is 60%. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

    Low: 70 °F

    Showers
    Likely then
    Chance
    Showers

  • Tuesday

    Tuesday: A slight chance of showers after 2pm. Mostly sunny, with a high near 92. Chance of precipitation is 20%.

    High: 92 °F

    Mostly Sunny
    then Slight
    Chance
    Showers

  • Tuesday Night

    Tuesday Night: Partly cloudy, with a low around 72.

    Low: 72 °F

    Partly Cloudy

  • Wednesday

    Wednesday: A chance of showers and thunderstorms after 2pm. Mostly sunny, with a high near 92. Chance of precipitation is 30%.

    High: 92 °F

    Mostly Sunny
    then Chance
    T-storms

  • Wednesday Night

    Wednesday Night: A chance of showers and thunderstorms before 8pm, then a chance of showers between 8pm and 2am. Mostly cloudy, with a low around 74. Chance of precipitation is 30%.

    Low: 74 °F

    Chance
    T-storms then
    Chance
    Showers

Detailed Forecast

Overnight
Cloudy, with a low around 69. East wind around 5 mph.
Sunday
Patchy fog before 7am. Otherwise, mostly cloudy, with a high near 86. Southeast wind 5 to 10 mph.
Sunday Night
A slight chance of showers and thunderstorms, mainly between 10pm and 11pm. Patchy fog after midnight. Otherwise, mostly cloudy, with a low around 70. Southeast wind 5 to 10 mph becoming light and variable after midnight. Chance of precipitation is 20%.
Monday
A chance of showers, then showers likely and possibly a thunderstorm after 2pm. Patchy fog before 9am. Otherwise, mostly cloudy, with a high near 87. South wind around 5 mph. Chance of precipitation is 70%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Monday Night
Showers likely and possibly a thunderstorm before 8pm, then a chance of showers and thunderstorms between 8pm and 2am. Mostly cloudy, with a low around 70. Calm wind. Chance of precipitation is 60%. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.
Tuesday
A slight chance of showers after 2pm. Mostly sunny, with a high near 92. Chance of precipitation is 20%.
Tuesday Night
Partly cloudy, with a low around 72.
Wednesday
A chance of showers and thunderstorms after 2pm. Mostly sunny, with a high near 92. Chance of precipitation is 30%.
Wednesday Night
A chance of showers and thunderstorms before 8pm, then a chance of showers between 8pm and 2am. Mostly cloudy, with a low around 74. Chance of precipitation is 30%.
Thursday
A chance of showers and thunderstorms after 2pm. Partly sunny, with a high near 92. Chance of precipitation is 40%.
Thursday Night
A chance of showers and thunderstorms. Mostly cloudy, with a low around 75. Chance of precipitation is 40%.
Friday
A chance of showers and thunderstorms. Partly sunny, with a high near 91. Chance of precipitation is 50%.
Friday Night
A chance of showers and thunderstorms. Mostly cloudy, with a low around 72. Chance of precipitation is 40%.
Saturday
A chance of showers and thunderstorms. Partly sunny, with a high near 89. Chance of precipitation is 40%.
Basemap Options
Click map to change the forecast location
Loading map...
Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Princeton Junction NJ
 40.32°N 74.62°W (Elev. 85 ft)
Last Update:
1:08 am EDT Jul 13, 2025
Forecast Valid:
1am EDT Jul 13, 2025-6pm EDT Jul 19, 2025
 
Forecast Discussion
 
Get as KML Get as XML

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