Seychelles is often sold as a year round destination... and it is.
However there is more chance of bad weather, that is to say rain, in November and December. This can vary terrifically year to year - some years are very wet at this time, others are very dry and sunny. It is worth remembering that tropical islands do get rain all year round. That is why they have lush, green vegetation.
The driest month is August, sometimes extending into September, occasionally causing water restrictions.
At any time of the year it can be raining on one side of the island, and baking hot sunshine on the other! Half the year the winds are in one direction, stirring up the sea on that side of the island and occasionally causing seaweed on the beach. Then the other half of the year from the opposite direction.
The hottest month is April, but it is humid all year round..
From May to September, the winds pick up and you have the occurrence of the much talked about seaweed usually south or south-easterly of the respective island. It does not occur everywhere, but where it collects, it forms a soupy barrier is really impossible to swim through. If you are staying in a hotel (predominantly some beaches on Praslin are affected) that has the issue, they will always arrange for transport to a beach which is weed free.
One thing you can guarantee all year round, is that the temperatures are never, ever cold and of critical importance for those heading off on honeymoon between June and September, the temperatures are fantastic unlike other parts of the Indian Ocean.



