What are the temperatures around the tibetan plateau

Freezing and windy but dry in winter, and mild or cool in summer, with considerable variations between night and day, because of the strong sun's rays of high altitudes. The north is a bit colder than the south, but the temperature varies mainly with altitude; the only significant difference between the areas is that the eastern part is affected by the summer monsoon, so it receives a bit of rainfall (sometimes even abundant) in summer. Lhasa, the capital, is located in the eastern part of the province as well, while the central and western parts of Tibet are virtually uninhabited, since they are desert. While in winter the coldest areas of China are the northermost ones, in the other seasons the coldest region is Tibet, due to the high altitude.

Their solution was to tax the colonists.