My aunt went to Xining for a week in June 17, depending on the weather and temperature 15-27 degrees. What kind of clothes and articles should I bring? Thank you very much

I just came back from Xining last night and stayed for a week. Xining is 2200 meters above sea level, and it takes 3000 meters on the way to Qinghai Lake. Ultraviolet radiation is large, and the temperature difference between morning and evening is large. It rained a few days ago, and the temperature was very low, with a minimum of 2 degrees Celsius. Now it's nearly 30 degrees in the daytime, sometimes more than ten degrees in the morning and evening, and sometimes less than ten degrees. So in my experience, bring the following items: sun hat, sunglasses, sunscreen, sunscreen clothes, long-sleeved clothes and long-sleeved trousers for the elderly in case of low temperature when it rains.