May in Biysk averages a daily high of 20.6°C with nights around 5.8°C. Expect roughly 11.5 wet days totalling 56mm. Comfortable conditions for being outdoors all day.
Across the year, the best time to visit Biysk is May–September.
Based on BIJSK ZONALNAJA, RS (23.2km), 1995–2024. 30 years of May data.