December in Trenton averages a daily high of 7.2°C with nights around -1.3°C. Expect roughly 11.1 wet days totalling 101.4mm. A hard month to visit for comfort alone.
Across the year, the best time to visit Trenton is May–June.
Based on TRENTON MERCER AIRPORT, NJ US (9.1km), 1995–2024. 27 years of December data.