December in Yokosuka averages a daily high of 12.8°C. Expect roughly 6.2 wet days totalling 75.7mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Yokosuka is April–June.
Based on YOKOHAMA, JA (16.7km), 1995–2024. 25 years of December data.