What's the temperature like going to Yichun, Jiangxi for the Spring Festival in February? What to wear?

I can only tell you, take more clothes.

As an Yichun person studying in Taiyuan, I think it will be very uncomfortable for northerners to just arrive in the south because there is no heating. Even myself, after getting used to heating in the north, the feeling of staying at home is one word: cold! Clothes should be accompanied by down jackets. You'd better prepare a set of thermal underwear. These trousers should be thicker. Finally, bring a pair of cotton trousers. Put it on if you can't carry it.

However, after the spring, if it is sunny, it will be warm.

But personally, I suggest you take some thicker clothes. If it is cold, it will still help you.