I went to a site off the Sea of Cortez a few years ago at the end of the summer. The air/water were so hot/warm that it was hardly bearable. I was told that if I were to come back to do the same dives at the end of winter, I would want to be in a dry suit because the water would be so cold.
I think we need a little more information to give you good advice.
I think we need a little more information to give you good advice.