Every year since we have moved to this area we have went to see the manatees in the winter time. Any cold morning in the winter is a great time to see the manatees at Blue Spring State Park. This morning there were 233 spotted. I have been there when around 300 were there at once. Wall-to-wall manatees in the spring! It's great!
On a cold morning head out to Blue Spring State Park to see them. The park is located at 2100 W. French Road in Orange City. It opens at 8:00 a.m. If you are going to see the manatees on a cold morning in the winter you should make sure everyone dresses warm, take a camera, and arrive early. The longer you wait in the day you will risk not getting into the park, because they sometimes close it when it reaches capacity, or the manatees may head out to the river to eat. So arrive early and you will have no problem seeing all the manatee.
The manatee head to the spring on cold days because it always stays 72 degrees - all year! They seek refuge there, which gives us a wonderful chance to see them.
While you are there you can also watch a movie about them, visit a historical house (the Thursby house), take the little boardwalk nature trail, and even let the kids play on the playground, if it's not too cold. They also offer a wonderful nature boat ride at that park (and kayaking). Go back during the summer time to swim and tube in the spring!
There is also a manatee festival held each year. You can get all the details here.