Istanbul has all the seasons like winter, spring, summer and fall. So check the weather report before your visit.
The city is with more than 14 million people and very cosmopolite. Unlike some other muslim countries woman and man wear very modern clothings. I have seen in my last trips all of the famous brands thay have their own shops in Istanbul.
My suggestion is when you go to shopping or walking in the crowds wear more sport clothings, more modest you know... ( like a jean with jacket but not a leather one from D&G) When you go out for the night clubbing or dinner where more young people go out so you can wear short skirt or tank top if it is hot. For a man I think it is much easier to put on clothings.
In the mosques woman need to cover her head with cloth. Usually they give you at the entrance (it has to be free but I am not sure) I am a bit picky on higienic so I carry with me if I am going to visit one of these places. Man doesn't need to put any thing. Also you have to take out your shoes outside and leave them outside so If you wear comfortable shoes to take out it will be better for you. I carry also a plastic shopping bag to put my shoes in and carry with me when I visit a big mosque where so many people around. I am sorry I might be a bit paranoid but i can not help it :))
I don?t profess to be an expert after less than a week in Istanbul, but in the short time I was there, I found the whole ?fashion scene? tremendously interesting. People are always going on about how Istanbul is a blend of East and West. Well, that may be true to an extent, but I definitely felt that I was more in the East. Despite all the talk about Turkey banning headscarves, I saw them everywhere, on women young and old, including on the campus of Istanbul University.
These scarves added a vibrant splash of color, and while they did cover the women?s hair in keeping with Islamic ideas of modesty, they were clearly a fashion statement. Coming from Israel, where headcoverings for women are also very common, I noticed a difference in the way the scarves are worn. They don?t follow the contours of the head, but seem to bulge slightly in the back. My guess is that some kind of form is worn underneath to get that elongated shape. The most interesting thing was that many of these girls in headscarves were also wearing tight jeans and revealing tops. Some were walking hand in hand with their boyfriends.
Other women were swathed from top to toe in black abayas. Sometimes their faces were uncovered, and sometimes the black veiling was clipped tightly over their noses, leaving only their eyes visible. Incongruously, these same pious ladies were accompanied by men in sleeveless undershirts and fashionably torn jeans.
It is customary to leave your shoes outside the door when entering Turkish homes. When you have walked the streets of Istanbul you will know why! They are muddy and filthy and you don't want to be traipsing it into your hosts home! Our hosts gave us some indoor shoes to wear.
Turkey is a secular European republic.
Women are free to wear whatever they want here.
A minority of women wear headscarves, but most of those wear modern ones which they mix with jeans and shirts like anyone else.
If you wear a headscarf, please remember that you won't be allowed to enter certain places such as universities and public offices.
Men dress as in Europe.. Nothing is different here.
If you see women wearing a full black veil (very rare), then they are often Arabs.
First of all,Istanbul is not a part of the Orient and the normal dress code is not different from the rest of Europe..
But you should consider to choose your clothes due to weather conditions..
The winter is chilly (December-March)
The spring is warm
Summer ( June-September) is relatively hot..
Women in Turkey sometimes wear traditional costumes & cover their heads with a veil which is called the mahrem consisting of 2 pieces of muslin; the 1st covered the face up to the nose while the 2nd was wrapped around their head & neck & knotted.
Dress conservatively. It's not that all women in Turkey wear chadors (full black with veil), but you'll get hassled a lot less if you are wearing pants or a conservative skirt. If you go into a mosque (as a woman) make sure to cover your head, and ideally put on long sleeves. It's just respect. You can buy head scarves for cheap outside of larger mosques, or you can borrow one. People do dress up in miniskirts, etc for clubs, but if you are traveling alone and are out at night, I'd stick with nice pants.
After seeing several shops in Istanbul that displayed costumes such as the one on this manequin, I learned the Turkish custom of circumcission. Although performed by Christians and Jews alike during the first week of a baby boy's life, here they must wait until the age of 6-7, the last summer before entering school. In the morning of the big day, boys are dressed in their costume and treated like little princes - they receive gifts and money from relatives and they are taken wherever they choose to go. That evening the rite takes place either at a clinic or at home by a specialist, without anesthetic. At this point, the young Turk becomes a boy and he must complete military service before being considered a man.
I've never seen somebody on the street with this dress.. You can see it only in a museum.. It's from Ottoman times.. Very fancy, isn't it 8)?