August in Seongnam-si averages a daily high of 29.9°C. Expect roughly 15.3 wet days totalling 548.5mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Seongnam-si is June.
Based on SEOUL CITY, KS (20.8km), 1995–2024. 22 years of August data.