August in Puerto Penasco is the hottest month of the year. In August, the weather in Puerto Penasco is typically hot. Average daily high temperature in August is about 34 degrees above zero. On average, Puerto Penasco has 26 sunny, 4 partly cloudy, and 1 rainy day in August. The rains are usually light. August as well as July and September is considered the most uncomfortable time to visit Puerto Penasco.