February in Castanhal is the cloudiest month of the year. In February, the weather in Castanhal is typically hot. Average daily high temperature in February is about 30 degrees above zero. On average, Castanhal has 27 rainy and 2 cloudy days in February. The rains are usually heavy. February as well as January, March, April, and May is considered the most uncomfortable time to visit Castanhal.