Planning for the weather is a good way to make your trip to Mahajanga relaxing and enjoyable, especially when you're splurging. The hottest months are usually October and November, with an average temperature of 27°C, while the coldest months are July and August, with an average of 25°C. The rainiest months in Mahajanga are January, February, March and December, with each month seeing an average of 340 mm of rainfall.