Thanks for your answer. I believe so. I have searched a lot of information about the time to visit Tibet. It says that May to October is the best time. And I found this website is good for me because it gives me a lot of Tibet travel tips and so on. If you are interested in Tibet tour, you can visit it. www.greattibettour.com
If you are a foreigner, there are some restrictions for you. You should apply for the Tibet Travel Permit so that you can enter Tibet. The weather in October is cool, dry and sunny, so this month is quite suitable for Tibet travel. However, if you want to travel to Tibet in October, try to avoid Oct.1st to 7th. Because it is the Chinese National Day, and many Chinese would rush into Tibet during these seven days. In October, leaves and grasslands in Tibet turn from green to yellow, just like a fairy tale world. Meanwhile, the temperature difference between day and night is large in October. At daytime, it is around 12℃, and it drops to 2℃ at night. Thus taking some warm clothes is necessary.
Tibet is a high-altitude plateau with an average elevation of over 4,000 meters, so it tends to have a cool and dry climate with low atmospheric pressure and high UV radiation.
In general, the best time to visit Tibet is during the summer months (June to August) when the temperatures are milder and there is less chance of snow or rain. However, even in the summer, the temperature can drop significantly at night due to the high altitude. In the winter months (December to February), Tibet can be very cold and many areas become inaccessible due to heavy snowfall.
It's always best to check the weather forecast for the specific region you plan to visit in Tibet before your trip and to pack accordingly.