February in National Harbor is the windiest month of the year. In February, the weather in National Harbor is typically cold. Average daily high temperature in February is about 6 degrees above zero. On average, National Harbor has 12 partly cloudy, 8 sunny, 5 rainy, and 4 cloudy days in February. The rains are usually heavy. February as well as January, March, May, and December is considered the most uncomfortable time to visit National Harbor.