January in San Juan del Rio is the coldest month of the year. In January, the weather in San Juan del Rio is typically warm. Average daily high temperature in January is about 22 degrees above zero. On average, San Juan del Rio has 16 sunny, 8 partly cloudy, 5 cloudy, and 2 rainy days in January. The rains are usually light. January as well as February, November, and December is considered the most comfortable time to visit San Juan del Rio.