Weather is probably a major factor when you plan your trip to Lagoa Santa, but bear in mind that cheaper options are usually available when the weather isn't as good. The hottest months are usually September and October, with an average temperature of 23°C, while the coldest months are July and June, with an average of 19°C. The rainiest months in Lagoa Santa are December, January, November and March, with each month seeing an average of 243 mm of rainfall.