Taking into account the local weather in Planalto is an important factor for planning your visit, especially if you plan to spend your trip poolside. The hottest months are usually December and January with an average temp of 76°F, while the coldest months are July and June with an average of 64°F. The rainiest months in Planalto are October, January, December, and February, with each month seeing an average of 9 inches of rainfall.