As much as some will say you can kite until February or March in NE Brazil, I don't know anyone that will guarantee that.
January used to be the beginning of the rainy season in the area. Over the past 4 years, I have had rain start as early as January 17th and as late as March 23rd.
Fact: the further North you go, the windier it IS. This is valid for the windier months of September and October and for the rest of the year also.
Here in Prea, we usually get a lot kiters from Cumbuco or Paracuru towards the end of the year or beginning of January when the wind drops further South.
My 2 cents.