The overarching factor that affects the weather of the entire area, including most of Yunnan Province and parts of neighboring Myanmar and Sichuan Province, as well as Arunachai Pradesh, Bhutan, Nepal and Tibet (Tibet Autonomous Region), is that it is a highland plateau situated at a low latitude, very near the Tropic of Cancer. The peculiar combination of a high altitude – meaning a tendency toward cooler temperatures and clear, sunny skies – and a low latitude – meaning a tendency toward a hotter, more humid weather pattern – results in, for the most part, a climate that is characterized by cooler summers and warmer winters, combined with heavy rains in the monsoon period, but relatively clear weather throughout the rest of the year.
The exceptions to this general pattern are mountain tops, where it is cold year round (sometimes snow-capped year round as well), and the bases of deep gorges, which vary depending on whether they are located in the north of the province or farther south: deep gorges located to the north have hot, dry subtropical climates while deep gorges to the south have hot, humid subtropical climates, such as the climate around the wild elephant reserve, Xishuangbanna.
Another regularity regarding the climate of Lijiang, and Yunnan Province in general, is that the temperature swing is greater on a daily basis than it is on a season-to-season basis, meaning that layered clothing– at least the use of warm outer clothing in the mornings and evenings – is imperative.
The area around Lijiang in the north is the most typical for the province, with cooler summers and warmer winters, and with heavy rains concentrated in a distinct monsoon period, which makes the area very accessible to the tourist year round except for the worst parts of the monsoon period. Lijiang’s rainy season begins in May and ends in October, with the heaviest and most recurrent rainfall periods (some locals would swear that they can set their clocks by it) occurring during July and August, meaning that this is hardly the ideal time of year to visit the Lijiang area.
But like all highland areas that are bordered by mountains, the weather, due to highly fluctuating heat and wind patterns (the Indian Ocean to the south has great influence over the winds arriving here, including their temperature and water content), can change several times in a single day. In fact, there is an apt saying in the north of Yunnan Province that captures this climatic instability: “in the north of Yunnan Province, you can experience all four seasons within the span of a single day!”