I'm thinking of bringing my boys to DW just before they go back to school next September and I've heard that the crowds start to thin out the closer you get to the end of August. Here, the kids go back to school on the day after labour day. I know different schools go back at different times, but I just wanted to get a general idea of when it would be best to go. I will put up with the heat if it's exchanged for smaller crowds. Thanks for any input. 
