How busy are the Keys during Christmas?
I went during Easter one year and it was dead - a very good time to visit without tourist crowds.
Discussion
I have nothing to compare it to since I have never been here before. But, I'd say it's not busy though. It seems pretty dead. We haven't had to wait for any place we've gone thus far. We've only had two other boats with us at the reef and sandbar here in Islamorada. Key West seemed busier, but it wasn't mobbed. I want to come here again next year.
Best during the cold months, or else it is hella hot. New year’s eve is a fun party down there.