Weather in Chengdu

July is the warmest month (average 27.9°C, high 32.6°C) and January is the coolest (average 6.0°C, low 0.7°C). That 21.9°C swing in monthly averages is the first thing to plan around in Chengdu.

Rain is wet season runs from May to September, inside an annual total of 990 mm. The wettest month is July at 224 mm; the driest is December at 12 mm. Chengdu is in China at 30.7°N. The 2001–2020 NASA POWER daily record describes a humid subtropical climate. On this site the months that score closest to a 22°C day, lighter rain, and moderate humidity are April, May, and September.

Rainfall pattern

The wet season in Chengdu starts in May and ends in September (May, June, July, August, and September). July is the core of it at 224 mm. December is the other extreme, with 12 mm.

A rainy day here is a day with at least 1 mm in the NASA POWER series. July averages 22 such days; December averages 3.

Temperature through the year

Chengdu has a 21.9°C gap between its coolest monthly average (6.0°C in January) and its warmest (27.9°C in July). That is a northern-hemisphere pattern.

Mean high across all twelve months is 23.2°C and mean low is 12.6°C. These are 20-year grid averages, so a city station can read a few degrees warmer or cooler.

What stands out month by month

The year bottoms out in January. Plan for 0.7°C at night and 11.4°C in the afternoon. February: 14.8°C high, 3.1°C low, 14 mm rain, 72% humidity. In March, Chengdu averages 20.3°C by day and 8.1°C at night, with 33 mm of rain. April brings 60 mm and 13 rainy days; temperatures run from 13.2°C to 25.8°C. May is when the wet season typically starts in Chengdu: highs near 29.6°C, and rainfall jumps to 96 mm (17 rainy days). July is both the hottest and wettest month: highs around 32.6°C, 224 mm of rain, and 74% humidity.

August brings 201 mm and 21 rainy days; temperatures run from 22.3°C to 31.1°C. September closes the wet season: 127 mm over 20 rainy days, then the calendar dries. October stands apart from the months beside it: 22.8°C / 13.6°C and 59 mm. November brings 23 mm and 7 rainy days; temperatures run from 7.9°C to 17.8°C. December is the driest month, averaging only 12 mm across 3 rainy days. Highs sit near 12.3°C.

Best months to visit Chengdu

The three months with the highest comfort score are April, May, and September: April (19.5°C average, 60 mm, 63% humidity); May (23.5°C average, 96 mm, 62% humidity); September (23.0°C average, 127 mm, 78% humidity). They fall in calendar order. The score rewards averages near 22°C, lower rainfall, and humidity near 60%. It is a climate score, not a festival or price calendar.

If you want the wet season itself — fewer crowds, greener landscape, heavier rain — aim at May–September instead of the score.

How Chengdu compares inside China

Chongqing is about 269 km away: Chengdu is 0.5°C cooler than Chongqing in its hottest month and 152 mm drier over the year than Chongqing. Chongqing’s wettest month is June (205 mm) versus July here.

Xi’an is about 606 km away: Chengdu is about as warm as Xi’an at the hot peak and 298 mm wetter over the year than Xi’an. Xi’an’s wettest month is September (125 mm) versus July here.

Wuzhong is about 837 km away: Chengdu is 2.5°C warmer than Wuzhong in its hottest month and 761 mm wetter over the year than Wuzhong. Wuzhong’s wettest month is August (50 mm) versus July here.