Historical weather for Dec 13th 2012 in Toronto: http://climate.weather.gc.ca/climat...02-06-04|2015-02-10&Year=2012&Month=12&Day=13
Thanks matou. Below is a link that shows the daily data for the full month of December 2012. Note that there was no snowfall until later in the month, with no snow on the ground until the 27th (not the 29th as I had misread from a graph). This is the data used for Toronto and Mississauga and is usually representative of the GTA.
http://climate.weather.gc.ca/climat...ID=5097&Year=2012&Month=12&Day=26&timeframe=2