What should I wear to Guilin, Lijiang and Yangshuo on February 7th?

Generally speaking, you should wear a cotton-padded jacket.

If you are on the Lijiang River, it is easy to get windy, so it is necessary to bring a scarf, a hat and a sweater.

Yangshuo's words are similar to Guilin's.

Finally, observe the weather. If it rains or sleet, you should bring not only an umbrella, but also some hand warmers.

I'm just answering questions from the perspective of a southerner.

If you are a northerner, just follow the answer I gave above for reference.

I wish you a happy trip to Guilin!