China has real seasons, and the wrong month in the wrong place can ruin a trip. But the opposite is also true: the right off-season trip is often the best version of a destination. Here's when I'd go where, and when I'd stay home.
The two weeks to never travel
Chinese New Year (roughly late January to mid-February, shifting each year) and the October 1st 'Golden Week' are the two periods when 300+ million people travel at once. Prices triple, trains sell out a month ahead, and the Great Wall looks like a mosh pit.
If your only option is one of these weeks, go somewhere the Chinese don't — Harbin in late January is still excellent because the ice festival is long ended, and Dali in early February is almost empty.
Spring: March and April
March is cherry blossom season in the south — Guizhou, Wuhan, Nanjing all peak in mid-to-late March. Crowds are manageable outside the top two parks.
Early April is shoulder everywhere. Rapeseed fields peak in Wuyuan; the peaches flower in Linzhi (Tibet); and the gardens of Suzhou are at their best. Book two weeks ahead and you'll find flights and rooms 30–40% cheaper than peak.
Summer: the rule of altitude and latitude
June through August is hot and humid almost everywhere below the Yangtze. But summer is the only time to visit the north and west: Xinjiang is spectacular in July, the Tibetan plateau is warm enough to be pleasant, and Qinghai Lake's flower season is mid-July.
Avoid Shanghai, Guilin, and anywhere in the Pearl River Delta in July and August unless you really like humidity.
Autumn: the best month in China
Late October and November are magnificent. The Jiuzhaigou and Huangshan foliage peaks in mid-October; the Great Wall in November has clear skies, cold air, and tenth the crowds of September.
Yunnan's terrace rice harvest (Yuanyang) colours up in late October. This is my favourite month to take visiting friends anywhere in the country.
Winter: the underrated season
Harbin's ice festival runs from late December through February and is worth the cold. Beijing in December is clear and sharp; the palaces and the Great Wall empty out entirely.
Skiers should look at Changbaishan or the new resorts around Chongli. For sun, fly to Hainan — Sanya in January is the warmest place in China and cheaper than Phuket.
The takeaway
The cheat code: pick a destination first, then look up its two best months, then subtract one week on either end. That buffer is the sweet spot between peak scenery and peak crowds.