Being a vast country, Iran is home to wide variety of climatic conditions, so a decision about the best time to travel to Iran, totally depends on the regions and cities you plan to explore and the kind of weather you would prefer and enjoy.
Generally speaking, late March through May in spring, September and October in autumn are the best time to travel to Iran.
Try to avoid travelling during the New Year Holidays, from March 21st to April 1st as all sightseeing spots are very crowded.
For visitors who want to enjoy sightseeing without interference by tourist crowds, you can plan your private Iran tours between November and March 10th.
In June, July and August, in large part of Iran, the weather is sunny, dry and extremely warm. However, this does not apply everywhere for summer months such as northwest of the country.
Are you interested in more detailed information on the weather and climate in Iran?