Weather: in August, it is the rainy season, with monsoon rains in the mountains, but this year, so far, it has been quite dry, and you might just encounter the build up of clouds during the day, then a brief thunderstorm around 4pm with cooler temperatures - and then half an hour later, it will be clear.
In December, it gets very cold in the mountains at night. During the day it is usually fine, blue skies, but beyond Lijiang it can get cold and roads are sometimes closed with snow.
Tiger Leaping Gorge: a must-see in NW Yunnan, but the road into the gorge is still under construction. Check for up to date info.
Road: one challenge to travel in NW Yunnan is the on-going road closures and construction. Currently the road from Zhongdian to Deqin is closed and only open every 10 days, and the alternative route is also under construction, with the last part to Deqin very prone to landslides, slips and closures. So don't count on getting to Deqin.
Suggestions: outside Dali and Lijiang, there are many small villages which get very few outside visitors. I don't agree with the posters who suggest Shuhe rather than Lijiang old town. Shuhe is now overly-developed, charmless and expensive, whereas Lijiang old town still retains its charms and beauty, even if you have to share the experience with other tourists.
Equipment: don't take too much, you might notice how heavy it is climbing hills and stairs.
Acclimatize: in Dali, Kunming or Lijiang, before you go to Shangri-la. About 2/3rd of people coming from sea level to Zhongdian in a day will be affected by altitude. Drink lots of water.
If you require more information about the area or a foreign guide, contact me:
Keith Lyons, Lijiang Guides
keithalyons@gmail.com
I've been exploring the area since 1996, and living in Lijiang and Shangri-la since 2006.
We often run trips for photographers, and can help you get the best photos, and also have quality interaction with local people.
Recently we've taken an award-winning photographer from New York around Lijiang, and helped a magazine photographer get images for a book about the area.