March, April and May are high season in Iran, with gorgeous temperatures for sightseeing – but also higher prices, especially in April. You might be able to get a better deal in early June.
The ancient festival of Nowruz celebrates the Persian New Year and the coming of spring, and it’s the biggest event in the Iranian calendar. It usually runs from 20th March for around two weeks. This is a busy, expensive and chaotic time in Iran with many places closed for the celebrations, so unless you’re coming with the intention of joining in, it’s advisable to travel outside of this time.
Late November, December, January and February are bitterly cold – especially in the mountains of the north and west. July and August are boiling, with temperatures often into the 40s. This is doubly unpleasant as shorts and t-shirts are a no-no, and women must wear headscarves.
Ramadan is a month-long event in the Islamic calendar which shifts forward slightly each year. In 2017, it lasts from 27th May – 25th June, and in 2018 from 18th May. During Ramadan, it is forbidden to eat or drink in public between sunrise and sunset – although some restaurants may discreetly serve foreign tourists, and you can eat in private or in vehicles. After dark, be prepared for feasting.
September and October are also pleasant months to travel in Iran, and prices may well be slightly lower than in the spring.
Be aware that Friday is the Islamic day of rest. Friday and Saturday are the weekend; Sunday is a working day.