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.

Fair

66°F

19°C

Humidity 52%
Wind Speed Vrbl 7 mph
Barometer 30.18 in (1021.4 mb)
Dewpoint 48°F (9°C)
Visibility 10.00 mi
Last update 15 Oct 1:53 pm EDT
Extended Forecast for

Princeton Junction NJ

  • This Afternoon

    This Afternoon: Sunny, with a high near 66. East wind around 5 mph.

    High: 66 °F

    Sunny

  • Tonight

    Tonight: Showers likely and possibly a thunderstorm, mainly after 5am. Increasing clouds, with a low around 55. Calm wind becoming southeast around 5 mph after midnight. Chance of precipitation is 60%. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

    Low: 55 °F

    Partly Cloudy
    then Showers
    Likely

  • Friday

    Friday: Showers and possibly a thunderstorm before noon, then a slight chance of showers and thunderstorms after 5pm. High near 77. Southwest wind 5 to 15 mph. Chance of precipitation is 80%. New precipitation amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

    High: 77 °F

    Showers then
    Partly Sunny

  • Friday Night

    Friday Night: Showers and possibly a thunderstorm before 1am, then a chance of showers after 3am. Low around 45. West wind 5 to 15 mph. Chance of precipitation is 80%. New precipitation amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

    Low: 45 °F

    Showers then
    Chance
    Showers

  • Saturday

    Saturday: Partly sunny, with a high near 54. North wind around 15 mph, with gusts as high as 25 mph.

    High: 54 °F

    Partly Sunny

  • Saturday Night

    Saturday Night: Patchy frost after 5am. Otherwise, mostly clear, with a low around 34.

    Low: 34 °F

    Mostly Clear
    then Patchy
    Frost

  • Sunday

    Sunday: Patchy frost before 9am. Otherwise, sunny, with a high near 58.

    High: 58 °F

    Patchy Frost
    then Sunny

  • Sunday Night

    Sunday Night: Mostly clear, with a low around 37.

    Low: 37 °F

    Mostly Clear

  • Monday

    Monday: Sunny, with a high near 63.

    High: 63 °F

    Sunny

Detailed Forecast

This Afternoon
Sunny, with a high near 66. East wind around 5 mph.
Tonight
Showers likely and possibly a thunderstorm, mainly after 5am. Increasing clouds, with a low around 55. Calm wind becoming southeast around 5 mph after midnight. Chance of precipitation is 60%. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.
Friday
Showers and possibly a thunderstorm before noon, then a slight chance of showers and thunderstorms after 5pm. High near 77. Southwest wind 5 to 15 mph. Chance of precipitation is 80%. New precipitation amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.
Friday Night
Showers and possibly a thunderstorm before 1am, then a chance of showers after 3am. Low around 45. West wind 5 to 15 mph. Chance of precipitation is 80%. New precipitation amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Saturday
Partly sunny, with a high near 54. North wind around 15 mph, with gusts as high as 25 mph.
Saturday Night
Patchy frost after 5am. Otherwise, mostly clear, with a low around 34.
Sunday
Patchy frost before 9am. Otherwise, sunny, with a high near 58.
Sunday Night
Mostly clear, with a low around 37.
Monday
Sunny, with a high near 63.
Monday Night
Partly cloudy, with a low around 40.
Tuesday
Mostly sunny, with a high near 67.
Tuesday Night
Partly cloudy, with a low around 44.
Wednesday
Sunny, with a high near 66.
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ABOUT THIS FORECAST

 
Point Forecast:
Princeton Junction NJ
 40.32°N 74.62°W (Elev. 85 ft)
Last Update:
2:27 pm EDT Oct 15, 2026
Forecast Valid:
2pm EDT Oct 15, 2026-6pm EDT Oct 21, 2026
 
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Additional Resources

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Hourly Weather Forecast

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High Temperature

National Digital Forecast Database Weather Element Forecast

Chance of Precipitation