December in Lomza is the windiest month of the year. In December, the weather in Lomza is typically cold. Average daily high temperature in December is about 1 degree above zero. On average, Lomza has 15 cloudy, 11 rainy, 4 snowy, and 1 sunny day in December. The rains are usually moderate. December as well as March and November is considered the most uncomfortable time to visit Lomza.