Hi Jessica! March has arrived and it sounds like your wonderful Walt Disney World vacation is just around the corner. You must all be so excited for this great vacation and to introduce your son to the world of magical experiences.
I am actually here right now at Walt Disney World. The weather is beautiful and predicted to stay that way for the next week. The weather generally in this month is warm but not hot and it also is not considered to be too humid. That does not mean the sun won't be out and burning. Bringing a young infant will mean you definitely will want to keep a hat on his head and sunscreen on him at all times. And don't forget to reapply the sun screen every few hours.
Early morning and later in the evening the temperature can cool off. Think about layers with a light wrap for those times but shorts and tops for during the daytime hours. If you don't keep socks on his feet make sure you keep sunscreen on them as they will burn if not protected.
When you head to the parks remember that each one will have a fully equipped
Baby Center where you can stop and rest in a cool and quiet environment. There are changing tables and quiet rooms where mothers can nurse or feed their children. There is a cast member on duty at all times to help you if you need to purchase supplies such as diapers, food, formula, and certain over the counter medicines. If you leave your resort room in the morning and realize once the sun is out that you haven't put the sun screen on or have left the hat on the bed then never worry as these Baby Centers will have what you need.
Have a magical vacation!