Nyingchi in September is still rainywith an average temperature of about 18 °C. Nyingchi still feels warm and damp in the late summer and it feels comfortable. The leaves begin to turn yellow while the sky gets even bluer and the lake becomes clearer. At this time, a light sportswear will be good for hiking or enjoying a picnic by the lake inNyingchi.
Daytime average temperature: 20°C, light cotton or linen clothes such as sports T-shirts/pants, jeans, light jackets, etc. are recommended.
Nighttime average temperature: 10°C, warm clothes such as wind breakers, light sweaters, jackets, sportswear, etc. are recommended.
Nyingchi dose not only looks good when the peach blossoms blooming. The summer in Nyingchi is always with a small breeze around 20° C, and there are not many tourists. Mount Nanga Bawa is playing hide-and-seek in the clouds. Lulang Forest Sea, Bomigang Spruce Forest, the secret lotus flower Motuo are green everywhere with the clouds steaming and fogging. Various flowers and plants in Nanyi Valley are flourishing and blooming.
Because of the strong UV radiation, no matter which season you pick to travel to Tibet，sun protection is needed.
The temperature difference between day and night can be really large in Tibet and you are recommended to be aware of it to stay well. Catching a cold can be dangerous due to high altitude complications.
When you first travel to the Tibetan Plateau, most people will feel different levels of hypoxia such as chest tightness, difficulty breathing or other symptoms. But this does not mean that you cannot adapt to the high altitude environment. If you can adjust yourself properly, the above symptoms can generally be improved or disappear in 2~3 days.
September is the peak season for travel to Tibet. It is recommended to plan and book your hotels and plane/train tickets in advance, since the accommodation and tickets can be difficult to get. Even a ticket for visiting Potala Palace may be really hard to book then.
August is also the rainy season in Tibet. If you are hiking to Ali and Medog, please be aware of the possible natural disasters such as landslides and mudslides. It is recommended to know the local weather before you go.