Deciding on what to wear when traveling in Iran can be a little intimidating. But the reality is that you will find that most women actually wear western clothes and they are not as conservative as other Muslim countries.
You will have to cover your hair, but not entirely and you actually see a lot of women that have most of their hair in the front of their head uncovered. Normally a scarf around your head, tied under your neck is enough, or you can just use the scarf around the head and then throw over your shoulder each of the corners. I prefer to tie it, as it keeps it in place for longer and it also reminds me a bit of my great grand mother, who I never saw without a cute silk scarf around her head. You can also place it as in the GCC countries (which is much tighter and covers the whole hair) but you will see it mostly in the smaller towns and villages.
With regards to the clothes, loose clothes are the solution. During Summer you will notice most women either use loose long skirts (like the one I have in the header photo) or long trousers. In main towns they actually wear skinny jeans as well always making sure they have a long top or mid length loose dress that covers their figure – normally about knee length or even less (the key is to literally cover your, how shall I put it, ‘derrière’). Make sure it has long sleeves or wear long sleeves or 3/4 sleeves underneath it. Initially I didn’t think 3/4 length was acceptable but now I realise everyone also uses them.
I brought with me a long skirt, a couple of lightweight trousers (that can also become shorts), some tops/t-shirts and a jeans jacket. I wore a tight long sleeves top with a loose blouse on the second day and it was just too hot and sticky, I could barely breathe! So now I’m trying to wear clothes that are as loose as possible… sticking to the skirt with a tshirt and the jeans jacket ( which is actually quite light and fresh) to cover my arms.