Firstly, you seem to be among the many who can't see a box to post the substance of your question in. Then, when you've managed to ask about the temperature in Tunisia (by posting a separate question), I can't see a link allowing me to answer it on that thread!
just to add to Chris's answer, I was in Port El Kantaoui in December and it was close to freezing. Fine if you were in the sun and out of the wind, extremely nippy at other times. Wrap up if you want to do daytrips inland to hilltop Roman ruins.
But I've also been there over Christmas and it was mild and sunny, about 15 degrees C. So take layers and be ready for anything.