Weather is probably a major factor when you plan your trip to Yiyang, 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 27°C, while the coldest months are January and December, with an average of 9°C. The rainiest months in Yiyang are June, May, July and April, with each month seeing an average of 235 mm of rainfall.