Nanchang has a humid subtropical climate with monsoons (Köppen Cfa) and four distinct seasons.
Winters are short and cool with occasional frosts. Winter begins by being somewhat sunny and dry but becomes progressively wetter and more overcast.
The start of spring is especially gloomy. From April to June, every month has more than 220 mm (8.7 in) of rainfall.
Summer is long and humid. The high temperatures of any Chinese provincial capital are recorded in here. In addition, the sun shines close to 60% of the time in July and August. This is the sunniest time of the year.
Autumn is warm to mild with the low rainfall levels of the year. The monthly 24-hour average temperature ranges from 5.3 °C (41.5 °F) in January to 29.2 °C (84.6 °F) in July. The annual mean is 17.63 °C (63.7 °F). The annual precipitation is around 1,620 mm (64 in). The monthly percentage of possible sunshine ranges from 23% in March to 60% in August. The city receives 1,820 hours of bright sunshine annually.