If you're hoping to get lost in the rain on your romantic getaway, take a look at these details about year-round temperatures in Grand-Bassam: The hottest months are usually April and March, with an average temperature of 28°C, while the coldest months are August and September, with an average of 25°C. The rainiest months in Grand-Bassam are June, May, October and July, with each month seeing an average of 250 mm of rainfall.