December is Mozambique's summer and South Africa's holiday. From the middle of the month the village fills, the beach bars run late, and a coast that spends eleven months empty becomes a place with a queue at the good restaurant.
That is worth planning around in both directions. If line-ups of four are the reason you were considering Mozambique, take the first half of the month or go in September. If a week in warm water with a beach, a market, a lot of diving and some company sounds better than a week alone with a point break, this is the month that offers it, and the surf is small enough not to complicate anything.
The water is at 27°C and climbing, the rains are properly established, and the cyclone season is a month from its peak. Nothing about December here is about the waves.
