Chengdu, the capital of Sichuan province, sits on a fertile plain within the mountain-ringed Sichuan Basin in southwestern China at approximately 30.57°N, 104.07°E. Sheltered by surrounding highlands, it has a mild humid subtropical climate (Köppen Cwa) — with hot, humid summers and mild, damp winters — but is above all famous for its persistent cloud, high humidity and notably low sunshine.

Summer, from June to August, is hot and humid, with July and August the warmest months — average highs around 30–31°C — and the wettest, most oppressive season, when the summer monsoon brings frequent heavy rain and thunderstorms, often at night. The basin traps warm, moist air, so the heat feels muggy and the humidity is relentless, though the surrounding mountains keep extremes in check.

Winter, from December to February, is mild but damp, chilly and grey, with January the coolest month — average highs around 10°C and lows near 3–5°C, rarely reaching frost. Snow is very rare. The defining feature is gloom: the basin traps persistent fog, mist and low cloud, so winter is overcast and raw-feeling despite the mild temperatures, with very little sunshine.

Chengdu receives around 900–1,000 mm of rain a year, concentrated in the summer months from June to September, often falling at night, while winter is drier but persistently damp and cloudy. Sunshine is famously scarce — among the lowest in China — with the basin under cloud much of the year. Live rainfall, humidity, and pressure readings for the city are shown in the panels above.

Chengdu's mountain-ringed basin is the key to its weather: it traps moist air to produce persistent cloud, fog and humidity, making the city one of the least sunny in China — an old saying holds that Sichuan dogs bark at the sun, so rarely does it appear. The muggy, overcast character pervades the whole year, with damp, grey winters and humid, rainy summers, and the sheltering mountains keeping temperature extremes mild.

To follow any single measurement in Chengdu more closely, use our live instruments: the online barometer for atmospheric pressure, the thermometer for temperature, the hygrometer for humidity, the anemometer for wind speed, the wind vane for wind direction, and the rain gauge for rainfall.