Do you mean in weather or crowds or both?
Weather here between the weeks isn't much different. Not sure about school schedules but normally spring break isn't until the 2/3rd week in March. You should be ok with crowds. It does start to bulk up in March though.
Weather should be fairly warm. In the 80's and 70's at night. We still could get a cold snap but it's usually warming up by then. Warning though. It is Oak tree season here then so if you have seasonal hay fever type allergies, be prepared to have them while you are at WDW during this time frame.