Planning for the weather is an important factor for making your trip to Antananarivo a success, especially when you're splurging. The hottest months are usually November and October, with an average temperature of 20°C, while the coldest months are July and August, with an average of 15°C. The rainiest months in Antananarivo are January, February, December and March, with each month seeing an average of 311 mm of rainfall.