August in Wŏnsan averages a daily high of 27.7°C with nights around 21.7°C. Expect roughly 15 wet days totalling 475.4mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Wŏnsan is September–October.
Based on WONSAN, KN (3.5km), 1995–2024. 19 years of August data.