Why is the sky blue in Lhasa?

When sunlight enters the atmosphere, colored light with a longer wavelength, such as red light, has a large transmissivity and can penetrate the atmosphere to the ground; The violet, blue and cyan light with wave length is easy to scatter when it encounters atmospheric molecules, ice crystals, water drops, etc. Scattered purple, blue and cyan light fills the sky, making the sky appear blue.

When is the best month to travel in Lhasa?

The best travel time to Lhasa, Tibet is from July to September every year. Lhasa, known as the "Sunshine City", has a long sunshine period, mild climate, no hot summer and no cold winter. The highest temperature in the year is in June in summer and the lowest temperature is in January in winter. There is little rainfall in Lhasa, but it is obvious in dry and wet seasons. The rainfall is mainly concentrated in July, August and September, and mostly falls at night.