September in Vyborg averages a daily high of 15.4°C with nights around 8.6°C. Expect roughly 11.8 wet days totalling 67mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Vyborg is June–August.
Based on VYBORG, RS (2.9km), 1995–2024. 30 years of September data.