Taking into account the local weather in Riobamba is an important factor for planning your visit, especially if you plan to spend your trip poolside. The hottest months are usually October and November with an average temp of 52°F, while the coldest months are August and September with an average of 50°F. The rainiest months in Riobamba are April, March, February, and January, with each month seeing an average of 22 inches of rainfall.