January in Puerto Iguazú is the hottest month of the year. In January, the weather in Puerto Iguazú is typically hot. Average daily high temperature in January is about 30 degrees above zero. On average, Puerto Iguazú has 20 rainy and 11 sunny days in January. The rains are usually heavy. January as well as February and December is considered the most uncomfortable time to visit Puerto Iguazú.