Toronto is sunnier than Vancouver but the sun is not very strong. Like I said it is warm in July and Aug (often 30+ C temps). End of Aug temp is going down fast very fast. In a few days it can go from 30 to 15. Sept to June (in my books it is winter) temp ranges from -25 to +15/16 with a few days in Oct (indian summer) and Apr that can go to 20-24. -10 and sunny in the winter is normal.

Some people (those who live there for years) think that in the recent years winters are milder but I was there in Dec and it was pretty much the same story. Many days -5 to --8 heavy snowstorms etc.