Weather in Nanjing

Rain is wet season runs from June to September, inside an annual total of 1196 mm. The wettest month is July at 243 mm; the driest is December at 42 mm.

Nanjing is in China at 32.1°N. The 2001–2020 NASA POWER daily record describes a continental climate with a wide temperature swing. July is the warmest month (average 28.4°C, high 32.2°C) and January is the coolest (average 2.8°C, low -2.0°C). On this site the months that score closest to a 22°C day, lighter rain, and moderate humidity are May, June, and September.

Hot and cool months in Nanjing

Monthly average highs run from 7.5°C in January to 32.2°C in July. Nights follow the same curve: -2.0°C in January and 24.6°C in July.

Mean high across all twelve months is 21.4°C and mean low is 11.2°C. These are 20-year grid averages, so a city station can read a few degrees warmer or cooler.

Rain through the year

The wet season in Nanjing starts in June and ends in September (June, July, August, and September). July is the core of it at 243 mm. December is the other extreme, with 42 mm.

A rainy day here is a day with at least 1 mm in the NASA POWER series. July averages 16 such days; December averages 7.

Distinctive months in Nanjing

The year bottoms out in January. Plan for -2.0°C at night and 7.5°C in the afternoon. February: 10.5°C high, 0.1°C low, 64 mm rain, 78% humidity. In March, Nanjing averages 15.9°C by day and 4.1°C at night, with 70 mm of rain. April brings 95 mm and 9 rainy days; temperatures run from 10.0°C to 22.1°C. May stands apart from the months beside it: 27.5°C / 15.8°C and 87 mm. The wet season opens in June. Expect 181 mm and 12 rainy days, with nights around 20.6°C.

July is both the hottest and wettest month: highs around 32.2°C, 243 mm of rain, and 82% humidity. August brings 156 mm and 15 rainy days; temperatures run from 24.1°C to 31.9°C. September closes the wet season: 94 mm over 9 rainy days, then the calendar dries. October stands apart from the months beside it: 23.6°C / 12.6°C and 55 mm. November brings 59 mm and 7 rainy days; temperatures run from 6.1°C to 17.0°C. December is the driest month, averaging only 42 mm across 7 rainy days. Highs sit near 9.6°C.

Best months to visit Nanjing

The three months with the highest comfort score are May, June, and September: May (21.7°C average, 87 mm, 71% humidity); June (25.7°C average, 181 mm, 74% humidity); September (23.7°C average, 94 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 June–September instead of the score.

How Nanjing compares inside China

Hefei is about 143 km away: Nanjing is about as warm as Hefei at the hot peak and 43 mm wetter over the year than Hefei. Hefei’s wettest month is July (227 mm) versus July here.

Hangzhou is about 237 km away: Nanjing is about as warm as Hangzhou at the hot peak and 230 mm drier over the year than Hangzhou. Hangzhou’s wettest month is June (230 mm) versus July here.

Shanghai is about 270 km away: Nanjing is 0.4°C cooler than Shanghai in its hottest month and 89 mm drier over the year than Shanghai. Shanghai’s wettest month is June (195 mm) versus July here.