In New England, we get a lot more cool/cold weather than warm weather. The real problem is the humidity. I can take 85 degrees (30 C) with low humidity; I can't take it with 90% or higher humidity. I have two window A/C units, one for the kitchen and one for the living room, and they get turned on when the temperature is over 85 and the humidity is over 80%. Otherwise, I just keep the shades down and curtains closed during the hot parts of the day and the house stays cool enough for me.
We have a ceiling fan in the dining room that is perhaps the most ugly ceiling fan I have ever seen, but it does keep things cool. So on hot summer nights when we don't need the A/C, we mostly move all activities into the dining room. We use window fans in the bedrooms to cool things down at night.
Our cooling season generally runs from late June to the end of August, but the past few years, we've had a few days in the 90s (above 32 C) in the beginning of June. No one has been prepared for that.