August in Estoril is the warmest month of the year. In August, the weather in Estoril is typically warm. Average daily high temperature in August is about 19 degrees above zero. On average, Estoril has 22 sunny, 8 partly cloudy, and 1 rainy day in August. The rains are usually light. August as well as July is considered the most comfortable time to visit Estoril.