Visiting local bars in Altamira is more fun when you know what the weather holds. These rainfall averages and temperatures can help you decide the best time for bar hopping. The hottest months are usually September and October with an average temp of 83°F, while the coldest months are July and June with an average of 78°F. The rainiest months in Altamira are April, March, February, and January, with each month seeing an average of 14 inches of rainfall.