In August, the weather in Foz do Iguaçu is typically warm. Average daily high temperature in August is about 23 degrees above zero. On average, Foz do Iguaçu has 16 sunny, 7 partly cloudy, 6 rainy, and 2 cloudy days in August. The rains are usually heavy. August as well as September is considered the most comfortable time to visit Foz do Iguaçu.