In August, the weather in Ostashkov is typically warm. Average daily high temperature in August is about 20 degrees above zero. On average, Ostashkov has 12 sunny, 10 partly cloudy, 6 rainy, and 3 cloudy days in August. The rains are usually light. August as well as {{month_nom: February}}, and {{month_nom: February}} is considered the most comfortable time to visit Ostashkov.