For us, it's not normal to have 20C in the beggining of December. Tommorow, -1C and freesing rain. Then...Saturday through Wedsnesday: Snow and temps from 1C to -5C.
See here:
http://www.meteomedia.com/meteo/villes/can/Pages/CAQC0363.htm
See here:
http://www.meteomedia.com/meteo/villes/can/Pages/CAQC0363.htm