January in Lawrenceville is the coldest month of the year. In January, the weather in Lawrenceville is typically cold. Average daily high temperature in January is about 9 degrees above zero. On average, Lawrenceville has 13 sunny, 10 partly cloudy, 7 rainy, and 1 cloudy day in January. The rains are usually moderate. January as well as February and December is considered the most uncomfortable time to visit Lawrenceville.