September in Tønsberg averages a daily high of 17.2°C with nights around 9°C. Expect roughly 11.9 wet days totalling 112.9mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Tønsberg is June–September.
Based on MELSOM, NO (5.4km), 1995–2024. 23 years of September data.