Weather will likely play an important role when you plan your trip to Tres Ríos, but bear in mind that cheaper options are usually available when the weather isn't as good. The hottest months are usually March and February, with an average temperature of 21°C, while the coldest months are January and February, with an average of 20°C. The rainiest months in Tres Ríos are October, August, November and July, with each month seeing an average of 1052 mm of rainfall.