The best months to visit Iran are October and May. See monthly temperatures, rainfall and rain days (1991–2020 averages) to plan your trip.
Average daytime high and monthly rainfall in Iran: January 6°C / 41mm; February 8°C / 48mm; March 14°C / 61mm; April 20°C / 49mm; May 27°C / 22mm; June 33°C / 6mm; July 36°C / 4mm; August 35°C / 4mm; September 30°C / 4mm; October 23°C / 21mm; November 14°C / 46mm; December 8°C / 43mm.