We find unique and complicated climate in Tibet. Generally, the air is thin and low pressure with low oxygen. We find more sunny days in Tibet as the sun is strong and sunshine time is long. Temperature varies greatly between day and night. There is great difference in the climate between the northern and southern Tibet. A number of valleys in the south of Tibet have warm climate with great rainfall due to the influence of the humid air current from the Indian Ocean. The average temperature is about 8 degree celcious, the lowest temperature drop to -16 degree celcious. The highest temperature in those months comes up to 16 degree celcious. May to September is called the rainy season in Tibet. If we go to the north of Tibet, we find a typical continental climate. The average temperature drops below 0 degree celcious and the freezing season lasts for half of the year. Its highest temperature in July can't rise to 10 degree celcious. More rainfall in the night during the raining season and strong wind in winter is a common phenomenon. The whole year in Tibet can be divided into two different seasons: the dry season (October-April) and the rainy season (May –September).