In late June 1999, we visited Quebec City in the midst of a 'heat-wave' ...it was in the mid 90°F range.
Most buildings and vehicles there are sans-a/c. Add that to the humidity from being right on the St. Lawrence and the indigenous peoples were suffering. The news regularly reported heat related deaths and eagely forecast the weather, hoping for relief.
But to me, it was just like a pleasant springtime in Houston (but with cheap wine, fresh baguettes, better restaurants, beautiful scenery and friendly attitudes).