The best time to travel to Iran is in Spring (March, April, May) and Autumn (September, October, November), in those months you will find such a pleasant weather everywhere, not too hot and not too cold.

But to find good rate and if you don’t mind hot weather you can travel to Iran between June and September, also in winter that the weather is slightly colder.

You also should notice some ceremonies which is public holidays such as Iranian new year (21th march till 6th of April ) and Ramadan ( dates vary ) which eating and drinking is forbidden in public but its ok in hotels and Moharam ( dates vary ) and some other holidays which you can find them in public holidays link.