That is the tail end of spring break part two for some of the NY and north east schools. Seems like the schools that did spring break in two parts did part two either the second to last week or last week of April. The unofficial guide people are calling the crowd level a "3" which is what it would usually be at that time of year. To give you an idea, the only times its a "1" is between Turkey day and Christmas, and it's a "2" basically from Sept. till Turkey day. We were there last year around that time and although the MK seemed crowded at times, in general, there were really no issues with crowds.