December in Dayton averages a daily high of 4.9°C with nights around -3.3°C. Expect roughly 11.3 wet days totalling 80.5mm. A hard month to visit for comfort alone.
Across the year, the best time to visit Dayton is September–October.
Based on DAYTON MCD, OH US (2.5km), 1995–2024. 22 years of December data.