China Weather by Month: -21.7°C Nights in Harbin, 9.4°C Afternoons in Shanghai — the Same January

Harbin's January nights average -21.7°C, and its days only reach -11.7°C. Shanghai's January afternoons average 9.4°C. More than 30 degrees separate a Harbin night from a Shanghai afternoon, which is why "China weather in January" is a useless search when packing.

The five cities Koreans visit most fall into three groups. Beijing and Qingdao track Seoul's temperatures closely. Shanghai and Zhangjiajie have winters 7–10°C milder than Seoul's but more rain. Harbin is far colder, for far longer. And some variables matter more than temperature: spring dust, the June plum rains, and two holidays when hundreds of millions of people travel at once.

Beijing's January high is 2.4°C, essentially Seoul's 2.0°C. But January precipitation is 2 mm against Seoul's 18 mm, and spring (April) humidity drops to 38%. Your skin and throat notice first: moisturiser, lip balm and a mask matter as much as the right coat.

Summer runs in a different order from Seoul's. Beijing averages 15.7 days above 33°C in June, more than in rainy July (11.1). The dry heat before the rains is the fiercest. July and August then deliver more than half the year's rain in downpours.

Shanghai's plum rains (meiyu) start in mid-June and run into early July: 242 mm and 17 rainy days in June. Then comes the steam: July and August average about 13 days above 33°C each. October–November, clear and cool, is Shanghai's best season.

Zhangjiajie is southern too, but mountainous. April–May bring around 15 rainy days, so the peaks are often in cloud — ideal if you want the sea-of-clouds look, less so for clear views. For open vistas go in September–October, when rainy days drop to about 10. The summits are cooler than town, so carry a light layer even in summer.

Harbin's January: -11.7°C by day, -21.7°C by night, with sub-zero nights almost every day from November to March. That cold is the attraction. The Ice and Snow World and the ice-lantern festival open in late December to early January and are best in January, when nothing melts. March and November are just cold, with little to see.

Clothing advice is for Beijing — pack what you'd wear in Seoul that month. Go one step lighter in Shanghai in winter, and dress for a Seoul cold snap in Harbin from December to February.

1. Spring Festival (Lunar New Year) — trains and flights sell out and many shops close. It falls on 6 February in 2027.
2. Labour Day holiday (1–5 May) — the catch in lovely May: the Great Wall and the Bund are packed.
3. National Day holiday (1–7 October) — coincides with the best weather of the year. The real sweet spot starts the week after.
4. Shanghai, mid-June to early July — plum rains. Fine for museums; not for skyline photos.

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For China, check the calendar before the forecast. 1 October and 10 October have the same weather and completely different trips.

• Period and source: daily values from Open-Meteo's historical weather data (ERA5 reanalysis), 2016–2025, averaged by month at each city-centre coordinate.
• Versus official normals: reanalysis temperatures usually land within 1–2°C of station normals, but downpours get smoothed out, so monthly rain totals come out lower and rainy-day counts slightly higher.
• Rainy day: at least 1 mm of precipitation. Reanalysis picks up even light showers, so counts run high — especially in the tropics, where monthly millimetres are the better guide. Most tropical rain is an hour or two of downpour, not a washed-out day.
• Best months: a first pass from temperature, rainy days and humidity, then adjusted for seasonal factors such as the ice festival, spring dust and the Shanghai plum rains. It is a judgement call.