Ah, and remember, if the temp is around 70F, the locals may still be wearing long sleeves and if you are in a tank top people will be looking at you thinking.. When the sun goes down that girl is going to freeze!!
Ha so very true. I've lived in Wisconsin my entire life, and when I moved to Madrid my first thought was "wow, it's so nice and mild here during the winter". The second week I was there, it "snowed" (really, just a few flakes...the temp was still in the upper 40's). All the madrilenos were in giant parkas and hats and scarves and I was walking around in a long sleeved shirt and light jacket.
And, re: what I posted before about clothes...I didn't mean to imply that EVERY spaniard was compeltely fashionable and that an American would be completely out of place. Since I attended ICADE and lived in the Argulles/Moncloa ara, I was kind of on the upper end as far as fashions I saw on a daily basis. Here in the states, I'm a pretty casual dresser, but in Madrid I just didn't feel comfortable going to class in jeans and a hoodie because I knew I stuck out like a sore thumb.
I think the moral of the story is just wear what you find comfortable. But try to stay away from those oversized t-shirts that say 'proud to be an American"...