August in Winterthur is the sunniest month of the year. In August, the weather in Winterthur is typically warm. Average daily high temperature in August is about 22 degrees above zero. On average, Winterthur has 18 sunny, 8 rainy, and 5 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 Winterthur.