Weather is probably a major factor when you plan your trip to Greenville, and keep in mind that cheaper options are usually available when the weather isn't as good. The hottest months are usually April and March with an average temp of 81°F, while the coldest months are August and July with an average of 77°F. The rainiest months in Greenville are June, May, September, and October, with each month seeing an average of 12 inches of rainfall.