Yunnan boasts a large size and huge altitude differences, so it depends on where you want to travel in Yunnan.

In Kunming, the weather is cool in April, so you can just wear a shirt. However, when it rains, it becomes winter in Kunming, and the temperature difference between morning and evening is large, so you still need to bring a light jacket; if you go to Dali, Lijiang, and Northeast Yunnan, you need to bring a thick coat.

Outerwear.

But if you go to the lower latitudes of Honghe and Banna, you will really miss shorts and sandals. Remember to bring toilet water or something to prevent mosquitoes.

Yunnan belongs to the plateau. According to my business trip experience, it is drier and has stronger ultraviolet rays than Chengdu and Guangzhou. Many outsiders will feel their skin is dry (except for hot places such as Honghe, Banna, Lincang), so it is recommended to bring moisturizing and sunscreen skin care products.