The Tibetan climate is not as harsh as many people imagine it to be. It is suitable for travel to Tibet from April to the beginning of November, and the best time is August and September. But if you only stay in Lhasa, you can go there anytime of the year. Sun radiation is extremely strong in Tibet. The sunlight in Lhasa is so intense that the city is called Sunlight City. The thin air can neither block off nor retain heat so that the temperature extremes can be met in daytime and the same night respectively in Tibet. However it is not impossible to visit the holy snow land. May, June, September and October are the tourism season in Tibet.Most annual rainfall comes in the rainy season that starts from July to August. Usually it rains at night in Lhasa, Shigatse and Chamdo area.

For those who take tours in Tibet regions by road, travel in rainy season can be inconvenient and unsafe. Tourists are possible to encounter mudslides or accidents to block the roads and the uncertainty will affect your travel schedule.
If you are taking flights and your travel schedule is around Lhasa city, you won’t have much trouble with the bad weather. In this case, all these months are best time to travel in Tibet.

Weather in Tibet
Firstly, the weather in Tibet is not as hash as many people imaged. It gets warmer and warmer in recent year and most of the places you can visit all around the year, the temperature is about -15 to 20 degree. The big feature of Tibet climate is that it varies greatly within a single day. So, you may don't need the Air conditioner in Summer here. And another big feature is the different area, the climate is big different. In the same winter, the east of Tibet is quite warm in daytime but in west tibet (Ngari prefecture) is terrible cold and even down to -30degree in daytime.

Altitude in Tibet
An altitude over 3,000 meters is usually defined as high altitude, and most places in Tibet are higher than this level, especially North area of Tibet and west of Tibet. But most places of the south and east area may lower than this altitude. There is the altitude list of main places of Tibet.

Health Condition
According to the health sector and medical expert’s suggestion, if you are going to travel to Tibet plateau you'd better to take a medical examination, and if have any one of the following diseases should not enter to the places with altitude of 3000 meters or above:

1, All kinds of heart disease or obvious cardiac arrhythmia or resting more than 100 times / min, high blood pressure and all kinds of blood diseases, cerebrovascular diseases.
2, chronic respiratory diseases. Moderate obstructive pulmonary diseases such as bronchial asthma, bronchiectasis, pulmonary emphysema.
3, severe colds, upper respiratory tract infection, body temperature above 38 degrees Celsius, those persons should not enter Tibet before the recover.
4, high-risk pregnant women.

In a word, if your health condition is quite good, your places going to travel are not too high, you can just get there all around the year, sunch as Lhasa area, Tsedang Area, Shigatse city and Nyingchi area. Of couse, for the high places such as the Nagcku profecturea and Mt.Everest area, Mt.Kailash of Ngari prefecture, you'd better visit there in Summer.