January in Salto del Guairá is the hottest month of the year. In January, the weather in Salto del Guairá is typically hot. Average daily high temperature in January is about 29 degrees above zero. On average, Salto del Guairá has 23 rainy and 8 sunny days in January. The rains are usually heavy. January as well as February and December is considered the most uncomfortable time to visit Salto del Guairá.