May in Semnan averages a daily high of 30.9°C with nights around 19.1°C. Expect roughly 3.6 wet days totalling 11.8mm. Comfortable conditions for being outdoors all day.
Across the year, the best time to visit Semnan is March–April.
Based on SEMNAN, IR (9.4km), 1995–2024. 19 years of May data.