When to go: The best time of year to be in Tibet is between May and early November, after which temperatures start to plummet. Lhasa and Shigatse experience very mild weather between May and November although July and August can be rainy. These two months usually see around half of Tibet's annual rainfall.
Getting there: Flying from Chengdu (capital city of Sichuan Province) will be the most convenient way, there is more than one flight leave Chengdu for Lhasa every day. In addition, other big cities such as Beijing, Shanghai and Guangzhou also have direct flights to Lhasa.
There are long-distance buses to Lhasa from Chengdu, Lanzhou (Gansu Province), Ge'ermu and Xining (Qinghai Province).
Visa: Foreign visitors, in addition to a normal Chinese visa, must hold an Alien Travel Permit, issued by the Tibet Tourism Bureau (TTB).
Warning: People who suffer from high blood pressure or heart disease cannot travel to Tibet because of the high altitude stress.
How to prevent acute mountain sickness:
¡ñ Drink extra fluids. The dry air and evaporation of sweat may cause dehydration.
¡ñ Avoid alcohol as it may increase the risk of dehydration, and don't smoke.
¡ñ Avoid sedatives.
¡ñ Avoid catching cold before entering Tibet.

Shenzhen Daily