December in Union City averages a daily high of 7.1°C with nights around 0.9°C. Expect roughly 11.6 wet days totalling 111.9mm. A hard month to visit for comfort alone.
Across the year, the best time to visit Union City is May–June.
Based on NY CITY CENTRAL PARK, NY US (4.6km), 1995–2024. 30 years of December data.