Other facts from our historical weather data: Which months have the greatest rainfall in Gravel Bay? Most rainfall (rainy season) is seen in January, October, November and December. Which is the hottest month in Gravel Bay? September has an average maximum temperature of 30°C (86°F) and is the hottest month of the year. Which is the coolest month in Gravel Bay? The coolest month is January with an average maximum temperature of 27°C (81°F). Which is the wettest month in Gravel Bay? November tops the wettest month list with 307mm (12.1 in) of rainfall. Which is the driest month in Gravel Bay? April is the driest month with 31mm (1.2 in) of precipitation. Which is the sunniest month in Gravel Bay? April is the sunniest month with an average of 236 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.