August in Skien averages a daily high of 21.5°C with nights around 11°C. Expect roughly 15.7 wet days totalling 103.4mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Skien is June–September.
Based on GVARV NES, NO (30.1km), 1995–2024. 28 years of August data.