Yunnan
Yunnan Geography & Climate
Geography
Yunnan has more altitude range, more climate zones and more species than any other Chinese province, and the reason is the way the land is folded.
From tropics to snow
The lowest point is at 76 metres on the Vietnamese border, where the vegetation is tropical rainforest; the highest is Kawagebo at 6,740 metres in the north-west, which is glaciated and has never been climbed — an attempt in 1991 killed seventeen people and the local Tibetan community successfully campaigned for climbing to be banned on religious grounds.
Three Parallel Rivers
In the north-west the Yangtze, Mekong and Salween run north to south in separate gorges within about seventy kilometres of each other, divided by ranges rising thousands of metres between them. They then diverge to reach the sea in Shanghai, southern Vietnam and Myanmar. The area is UNESCO-listed and is among the most biodiverse temperate regions on earth.
Tiger Leaping Gorge
Where the Yangtze turns sharply north and cuts between the Jade Dragon and Haba massifs, the gorge is around 3,000 metres deep from river to summit.
The plateau and the karst
Most of the province is a plateau at 1,500 to 2,000 metres, with limestone in the east eroded into the pinnacles of the Stone Forest.
Where the plateau breaks up
Yunnan is where the Tibetan plateau collides with Southeast Asia and shatters. The ranges that run east to west across Tibet swing south here and are squeezed into a tight north-south bundle, which is what produces the parallel gorges and the extreme relief. It is still moving: the province sits on active faults and has had a series of destructive earthquakes, including at Lijiang in 1996 and Ludian in 2014.
Biodiversity
Yunnan holds roughly half of China’s plant and animal species on about four per cent of its land.
Climate Patterns
Yunnan’s climate is governed by altitude rather than latitude, and the plateau has one of the most agreeable climates in China.
The spring city
Kunming sits at 1,890 metres just north of the tropics, which produces an almost constant mild climate — around 20 to 24°C in summer and 8 to 15°C in winter, with more sunshine than most of China. It is known as the spring city and has been since the Tang dynasty.
Wet and dry
The year divides into a dry season from November to April — clear, sunny, cool at night — and a wet monsoon from May to October, when most of the year’s rain falls in heavy afternoon bursts and landslides close mountain roads.
The altitude range
The province spans everything. Xishuangbanna in the south is tropical, hot and humid year round. Shangri-La at 3,200 metres freezes in winter and is cool even in July. The north-western peaks carry permanent snow. A journey from Jinghong to Deqin passes through as many climate zones as a journey from Hainan to Heilongjiang.
Winter light
The dry season’s low-angle sun is what makes the flooded Yuanyang terraces photograph as they do, and it is the reason the season for them is November to March.
Eighteen oddities
There is a traditional list of the strange things about Yunnan — the eighteen oddities — and several are climatic: that four seasons occur on one mountain, that you can experience all of them in a single day, and that it rains in one valley while the sun shines in the next. They are folk sayings and they are also broadly accurate descriptions of what the topography does to the weather here.
Ultraviolet
High at altitude even when the air is cool.