January in Antrim is the windiest and the coldest month of the year. In January, the weather in Antrim is typically cold. Average daily high temperature in January is about 6 degrees above zero. On average, Antrim has 23 rainy, 4 cloudy, 3 sunny, and 1 partly cloudy day in January. The rains are usually moderate. January as well as February, March, April, and May is considered the most uncomfortable time to visit Antrim.