August in Antrim is the cloudiest month of the year. In August, the weather in Antrim is typically warm. Average daily high temperature in August is about 15 degrees above zero. On average, Antrim has 26 rainy, 3 cloudy, and 2 sunny days in August. The rains are usually heavy. August as well as January, February, March, and April is considered the most uncomfortable time to visit Antrim.