What clothes should I bring to study in Aachen, Germany?

It's windy here, hehe, the weather changes quickly. Take a strong umbrella ... it feels cold in winter and it's MINUS 20 at night, but don't worry indoors. It's enough to wear a shirt indoors with heating ... It's best to wear a thick coat outside, such as a scarf, hat and gloves, which can protect against the wind ... You can take it off indoors or on the bus. ...