What’s the weather like mid January/beginning February?

I’m going on a trip with my three year old to see my sister in law and brother, my sister in law is pregnant so we’re traveling to be there for the birth of the baby. I went around two years ago in November and it was pretty warm during the day but freezing at night, I wasn’t as prepared as I would’ve liked to have been.

So any tips or anything would be great. They live in Jacksonville Fl.