December in Salto del Guairá is the rainiest month of the year. In December, the weather in Salto del Guairá is typically hot. Average daily high temperature in December is about 29 degrees above zero. On average, Salto del Guairá has 24 rainy and 7 sunny days in December. The rains are usually heavy. December as well as January and February is considered the most uncomfortable time to visit Salto del Guairá.