The best time to visit Iran is from March to June
, when spring makes the country (which is generally very dry) green again and temperatures are mild throughout all the regions. Although it can be interesting to travel to Iran in winter (notably to visit the desert regions which are ordinarily hotter and the south of the country), temperatures can be glacial in the north and east. During July and August, temperatures can be suffocating and the sun can be scorching.
Best time to visit southern Iran and Shiraz
The best time to visit Shiraz is in spring, when the nights are warm but the daytime temperatures are still bearable. The city's gardens are covered in flowers and buds. From mid-June, the climate becomes really hot and dry.
Best period to see amazing Isfahan
The best time to visit Isfahan is in spring, when the nights are warm but the daytime temperatures are still bearable. From mid-June,, the climate becomes really hot and visits to the city are less pleasant.
Best time to visit Tehran and its region
Spring is the most pleasant time to visit Tehran. The New Year period is very unique, as the city's inhabitants leave town for 2 weeks and several museums close. In winter, the weather is cold and grey, but the ski slopes are very close for those who love to ski!
Best time to enjoy the Caspian Sea
It's best to visit this region in April/May, with temperatures and humidity rates still bearable. To discover the region's forests in their most beautiful finery, choose autumn.
Best period to visit northwestern Iran
It's most pleasant to visit Tabriz in May or June. You should avoid the winter months as temperatures can drop to -30°C.
Best time to visit central Iran and Yazd
As the central part of the country and Yazd are desert regions, opt to go there right at the start of spring. The nights can still be cool, but temperatures will be bearable in the day.
Best period to visit the eastern tip of Iran
As with the rest of the country, Mashhad should really be visited in spring. It's best to avoid the Shiite religious festivals (which follow the lunar calendar and change depending on the year), as the city's main attraction then becomes inaccessible.