Spring is finally here in Toronto too but it's probably not condensation. I don't think there is enough moisture in the small volume of air in an unoccupied car to cause what you've described. Leaves, dirt and especially pine needles will clog the drain holes pretty quickly if left unattended. Leaving a car parked with the sunroof open is often the cause, as well as opening the sun roof without clearing the debris that often settles around it's edge. Good luck.

Koz.

P.S. Just a friendly reminder, please turn your Caps. off when posting so people won't think you're yelling. Thanks.