May in Zanjan averages a daily high of 24.4°C with nights around 8.4°C. Expect roughly 8.8 wet days totalling 36mm. Comfortable conditions for being outdoors all day.
Across the year, the best time to visit Zanjan is September–October.
Based on ZANJAN, IR (16.4km), 1995–2024. 16 years of May data.