January in Alajuela is the sunniest month of the year. In January, the weather in Alajuela is typically warm. Average daily high temperature in January is about 23 degrees above zero. On average, Alajuela has 13 partly cloudy, 9 sunny, 5 cloudy, and 4 rainy days in January. The rains are usually light. January as well as February is considered the most comfortable time to visit Alajuela.