Now it is cold, people here wearing down coat, sweaters, scarves and winter shoes, it is even colder in the evening. Temperature is about 0-10C, better carry warm clothes with you. But it is hard to say if it will snow during your stay. You can find the newest Xian Weather(https://www.travelchinaguide.com/climate/xian.htm) information on this website.

thanks for the information!