I think Celsius is even better for knowing what to wear, because each degree difference actually means something. The difference between like 64 and 66 degrees in F is basically non-noticable. The difference between like 18 and 20 in Celsius is quite noticeable. Also every ten degrees of difference is Celsius is significantly different. -10, better bundle up. 0, make sure you've got a scarf. 10, maybe pack some gloves. 20 is pretty nice, light jumper maybe. 30? Damn it's hot. 40? Don't go outside. 50? Move. F isn't like that at all. What's the difference between 50 and 60? Not that much honestly.