Mozambique summertime is the best time to visit the Bazaruto archipelago.
December to April is the wet summer season in Vilanculos although it generally rains in brief at night refreshing the air .
The vegetation is super green and most flowers do bloom during this time. 
A boat trip to Bazaruto island is just superb  experience in summer. 
Climbing the Bazaruto island sand Dunes and having a full view of the northern and southern part of the ocean is amazing. 
Sometimes we could have heavy rain for few days, normally predicted in February but this year it is not happening in Mozambique according to the meteorological office.
This is the best suggested time to visit Bazaruto Archipelago and enjoy privacy and pristine nature as most people prefer not to visit Vilankulos during this period.
We will be very happy to assist you  during your holiday in Vilanculos exploring the beauty of Bazaruto islands.