Milan may be the fashion capital, but not everyone goes around in Armani. You'll find very well-heeled people and slobs as well. Looking out over the Piazza del Duomo for example, you'll see tons of sloppily dressed tourists, teenagers with the latest butt-exposing low-cut jeans, immigrant communities selling their wares or just generally congregating, business people rushing around - there are all kinds of dressing. It depends on where you go (dress up for a night on the town and go casual for walking around the city).

Wearing clean, white, shiny sneakers is a tip off that you are a tourist. While wearing shorts is absolutely fine for walking around, you'll also stand out as a tourist. You may not be admitted to churches if you are wearing shorts, tank tops or are showing your belly button. On the days you know that you want to go inside to visit places of worship it is a good idea to wear trousers. However, often you may run across churches you'd like to visit unplanned. If you're dressed decently enough (even in shorts) and feel comfortable that you're not going to offend anyone, go ahead and have a look. Large, tourist attracting churches like the Duomo have security checks at the door but most churches don't.

Another suggestion is to look up the webcams of Milan on before you go and check out what people are wearing on the streets (you can also check the current weather on the same website).

** Note:  The original information for this thread came from the following forum thread: