When you travel with your pet, keeping track of the weather can help you make the trip more safe and fun for everyone. The hottest months are usually September and October with an average temp of 73°F, while the coldest months are July and June with an average of 66°F. The rainiest months in Mogi-Guaçu are January, December, November, and February, with each month seeing an average of 9 inches of rainfall.