Known as a "fairyland on earth" by locals, Jiuzhai Valley is world-renowned for its natural beauty and draws in more than 2 million tourists every year.
Most visit during the warmer summer months, but in winter, Jiuzhaigou—a UNESCO World Heritage site—becomes a winter wonderland complete with huge snow drifts and frozen waterfalls, and best of all, very few tourists.
Although it may seem cold, with average mean temperature of minus 3.7 in January, adding a decent jacket and thermal underwear to your normal clothes should be plenty to allow you to brave the temperatures and venture forth.
The Jiuzhai Valley is home to Qiang and Tibetan villages—"Jiuzhai" refers to the nine originally in the area—a few of which can be explored freely by visitors.
During the winter, the park closes down most of the walking trails, but visitors can take a bus through the park (RMB80/90 off/on-season), stopping at some of the most popular sightseeing spots within the park, such as the five-color pond, Pearl Shoals Waterfall, and Mirror Lake.
If walking is more your style, it is recommended that you take the bus to the top of one of the bus routes and walk back down from there.
The biggest incentive to head to Jiuzhaigou in the winter is the price: RMB80 for a day pass, and RMB100 for two days (recommended), compared to RMB220 per day during peak season.
Hotels in area are also noticeably cheaper in the winter, with accommodations ranging from the five-star Sheraton (RMB600 to 800 per night) to Uncle Jiang's Family Guesthouse (RMB30 per bed or RMB100 for a double-occupancy room) to much-touted authentic Tibetan home stays (RMB180 per day per person, including three meals and transport to and from the park entrance).
All of these can be found with a cursory Google search; but make sure to check the actual location of the accommodation before booking as many hotels that claim to be inside the park can be as far as 20 kilometers away.