Weather is probably a major factor when you plan your trip to Rioja, and keep in mind that cheaper options are usually available when the weather isn't as good. The hottest months are usually September and October with an average temp of 69°F, while the coldest months are July and June with an average of 68°F. The rainiest months in Rioja are March, April, February, and January, with each month seeing an average of 13 inches of rainfall.