What to wear now in September?

Short sleeves and jacket, if you are afraid of the sun, you can wear long sleeves and jacket

Generally, long-sleeved shirts and T-shirts are available during the day, and jackets are required at night.

Just bring a coat. Mainly UV protection.

The temperature difference between morning and evening is large, you can use short-sleeved + long-sleeved shirts at noon, and down jackets at night