I do remember hot, humid summers in Montreal when I was young, though, and living without AC could be miserable. I still cringe when I hear the buzzing of telephone wires in the heat, as it reminds me of not being able to sleep due to the heat and humidity. That house was old and had small windows, so there was never much of a cross-breeze in the house. When we moved to Toronto we had AC, which didn't work well enough on the top floor, was just right on the ground floor, and left my basement bedroom so cold I could pack meat in it.
So you wouldn't be missing the hot humid weather that's been lingering over Ontario and into Quebec the past week or so. The predictions were that Toronto was going feel like it was 50C by the time the humidity was factored in though I don't think it was quite that bad.
I'm about 90mins North-East of Toronto and it was pretty bad but didn't hear what our temprature go to. All I know was at work (Call Centre) it was actually too damn cold but probably should be glad of that.
I'm also glad that the electricity is included in my rent so we don't have to pay the actually hydro costs for having the A/C (just an extra $25 a month for having the thing sitting in the window). the apartment would be almost unlivable without the A/C. Building ventilation system is only runnig some of the time and merely takes the air from outside and the windows are original from when it was build so there's not even any tinting.