Weather is one of the biggest concerns a traveler has, especially if visiting a country for the first time. With a country the size of China it is even more important as there can be extremes in climate from North to South especially in the winter.
The daytime temperatures in Harbin in the winter would be around -30C (-22F) and night temperatures even lower. While the temperature in Shanghai would be over 35C (95F) for most of summer. So before you travel to China it is strongly recommended that you check the weather conditions first. China is vast, and the climate and conditions vary widely from region to region.
If you choose the most attractive season to visit, you also choose the time when tourist spots and hotels are most stuffed. While China is a year-round destination, the months of May, September and October are ideal months to travel anywhere in the country.
In the north, the winters are cold, and summers are warm, with moist monsoon air streams making it hot (80% of China's rainfall occurs between late May and early October, mostly in Southern regions). June through August is a good time to visit central and northern China. Spring and autumn are the best months for travel in Southern China. The months of March and April are the lower-priced shoulder season; while the lowest price, off-season travel, is from November through the winter months. This is when adventuresome travelers are rewarded with unbelievably low prices and far fewer fellow tourists.
Regardless the time of the year, a visitor will always be rewarded with charming scenery throughout China.