Sir Please let me know the climate in four places of China

Hi, as for Shanghai and Beijing, it will be a little cool during that time, with the average temperature of around 13C. I suggest you take along long-sleeved and a light overcoat or windproof jacket.

For Xian, it will be still a little cold, with the average temperature of 9-10C. You may need long-sleeved shirt for sunny days, thin sweater and coat for rainy days and maybe overcoat for windy days.

Hong Kong is warm then, with the average temperature of about 22C. It would be cloudy and a little rain may fall from time to time. You can take along both long-sleeved and short-sleeved shirt as well as a light coat to keep warm at cool nights or rainy days.