Other facts from our historical weather data: Which months have the greatest rainfall in Discovery Bay? Most rainfall (rainy season) is seen in May, September and October. Which is the hottest month in Discovery Bay? July has an average maximum temperature of 32°C (90°F) and is the hottest month of the year. Which is the coolest month in Discovery Bay? The coolest month is February with an average maximum temperature of 28°C (82°F). Which is the wettest month in Discovery Bay? October tops the wettest month list with 171mm (6.7 in) of rainfall. Which is the driest month in Discovery Bay? February is the driest month with 49mm (1.9 in) of precipitation. Which is the sunniest month in Discovery Bay? April is the sunniest month with an average of 253 hours of sunshine. No idea where to travel to this year? We have a tool that recommends destinations based on your ideal conditions. Find out where to go with our weather planner.