January in Seongnam-si averages a daily high of 1.8°C. Rain is rare — about 1 wet days and 3mm across the month. Demanding conditions — pack for it and plan indoor options.
Across the year, the best time to visit Seongnam-si is June.
Based on SEOUL CITY, KS (20.8km), 1995–2024. 21 years of January data.