In December, the weather in Foz do Iguaçu is typically hot. Average daily high temperature in December is about 29 degrees above zero. On average, Foz do Iguaçu has 21 rainy, 9 sunny, and 1 partly cloudy day in December. The rains are usually heavy. December as well as January and February is considered the most uncomfortable time to visit Foz do Iguaçu.