September in Kotlas averages a daily high of 14.1°C with nights around 5.6°C. Expect roughly 14.6 wet days totalling 55.3mm. Demanding conditions — pack for it and plan indoor options.
Across the year, the best time to visit Kotlas is June–August.
Based on KOTLAS, RS (4.3km), 1995–2024. 29 years of September data.