August in St. Gallen is the sunniest month of the year. In August, the weather in St. Gallen is typically warm. Average daily high temperature in August is about 21 degrees above zero. On average, St. Gallen has 19 sunny, 9 rainy, and 3 partly cloudy days in August. The rains are usually heavy. August as well as {{month_nom: February}}, and {{month_nom: February}} is considered the most comfortable time to visit St. Gallen.