Other facts from our historical weather data: Which months have the greatest rainfall in Grand-Bourg? Most rainfall (rainy season) is seen in September and October. Which is the warmest month in Grand-Bourg? September has an average maximum temperature of 29°C (84°F) and is the warmest month of the year. Which is the coldest month in Grand-Bourg? The coldest month is February with an average maximum temperature of 27°C (81°F). Which is the wettest month in Grand-Bourg? October tops the wettest month list with 155mm (6.1 in) of rainfall. Which is the driest month in Grand-Bourg? March is the driest month with 46mm (1.8 in) of precipitation. Which is the sunniest month in Grand-Bourg? April is the sunniest month with an average of 245 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.