Weather will likely play an important role when you plan your trip to Jiujiang, but bear in mind that cheaper options are usually available when the weather isn’t as good. The hottest months are usually August and July, with an average temperature of 25°C, while the coldest months are January and December, with an average of 6°C. The rainiest months in Jiujiang are June, July, May and April, with each month seeing an average of 306 mm of rainfall.