May in Kostanay averages a daily high of 21.2°C with nights around 8.2°C. Expect roughly 8.9 wet days totalling 39.3mm. Comfortable conditions for being outdoors all day.
Across the year, the best time to visit Kostanay is May–September.
Based on KUSTANAI, KZ (0.6km), 1995–2024. 15 years of May data.