May in Kotlas averages a daily high of 16.2°C with nights around 4.1°C. Expect roughly 13.1 wet days totalling 50.7mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Kotlas is June–August.
Based on KOTLAS, RS (4.3km), 1995–2024. 30 years of May data.