August in Dundalk is the cloudiest month of the year. In August, the weather in Dundalk is typically warm. Average daily high temperature in August is about 16 degrees above zero. On average, Dundalk has 25 rainy, 4 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 Dundalk.