Weather will likely play an important role when you plan your trip to Serra, but bear in mind that cheaper options are usually available when the weather isn't as good. The hottest months are usually February and March, with an average temperature of 25°C, while the coldest months are July and August, with an average of 21°C. The rainiest months in Serra are December, November, October and March, with each month seeing an average of 182 mm of rainfall.