Though weather is just one factor, it can really affect your travel plans, especially when you are planning a longer stay in Umuahia. The hottest months are usually February and January with an average temp of 83°F, while the coldest months are August and July with an average of 78°F. The rainiest months in Umuahia are September, July, August, and October, with each month seeing an average of 15 inches of rainfall.