January in Fort Augustus is the windiest, the cloudiest, and the coldest month of the year. In January, the weather in Fort Augustus is typically cold. Average daily high temperature in January is about 2 degrees above zero. On average, Fort Augustus has 27 rainy, 3 cloudy, and 1 sunny day in January. The rains are usually heavy. January as well as February, March, April, and May is considered the most uncomfortable time to visit Fort Augustus.