August in Sundsvall averages a daily high of 20°C with nights around 10.4°C. Expect roughly 11.4 wet days totalling 93.4mm. Comfortable conditions for being outdoors all day.
Across the year, the best time to visit Sundsvall is June–August.
Based on SIDSJO, SW (1.5km), 1995–2024. 12 years of August data.