Getting an idea of what to expect from the weather in Puerto Iguazú will help you enjoy your stay to the fullest. The hottest months are usually January and December, with an average temperature of 26°C, while the coldest months are July and June, with an average of 18°C. The rainiest months in Puerto Iguazú are October, January, December and May, with each month seeing an average of 212 mm of rainfall.