When I lived in San Francisco (early 90s), my oldish apartment in the Mission not only had no AC (which I never missed) but no heat, except for an electric heater mounted on the wall of the hallway, as far as possible from all 3 bedrooms, which heated an area about 3 feet in diameter and caused the whole apartment to smell like burning hair. We all had space heaters in our bedrooms – it rarely (if ever) got below freezing while I lived there, but SF is much to cold and damp for no heat at all.
In Park City (7,000 ft) we do not have AC in the house and only on a few evenings have felt too hot, and then all it takes is keeping the bedroom windows open and things cool down pretty quickly. We are about to move into a house that does have AC , but I can’t see us using it.
When we lived in Buenos Aires and Kuala Lumpur AC was absolutly required.
I live in north Texas. Folks around here die every summer with no a/c. Literally, die. It gets hot. It always makes me think: people settled here before there was a/c AND they had to wear wool and vests and petticoats and keep their ankles covered?!?
Interestingly, temperature sensitivity seems to be at least somewhat culturally acquired, rather than physically inborn. There are several reports of feral children (kids that grew up alone in the wild for some significant period of time) seeming to be utterly impervious to heat and cold, sometimes stripping naked to go play in the snow.
Quickly thinking of a dozen friends and family near me in the 'burbs of Minneapolis - only I and a friend do not have central AC. I have a window AC in my living room, and ceiling fans in all but the bathroom. We put the AC in late June, have run it maybe 2-3 days/week since, mostly on cool/dehumidify. Today, at 83F with dewpoints in the low 60’s, it’s off. Tomorrow it’s supposed to be in the mid 90’s with the dewpoint around 70F. Yeah, it will be flipped on in the morning.
Every store / mall / restaurant has AC blasting.
I live at 8200ft in Colorado, we don’t need it and don’t have one. It’s funny seeing the people building a home across the street, they installed central air…license plate: South Carolina. They’ll find out soon enough that they don’t need it.
We don’t have it, though it wouldn’t be too expensive to install. Nights get cool enough that if you open up the house and run the fans you can get the temperature down pretty low, and our insulation is good enough so that closing the windows and shades when the outside heats up keeps the house cool almost the entire day. But new construction has AC because it is assumed a requirement.
Welcome to my world. I currently live in a Mission apartment built in 1906. No A/C, no heat in the bedroom. I don’t miss the A/C at all, but I live in multiple sweaters and throw blankets. It’s currently 57 degrees here.
My parents live in the North Bay. They have two heaters in the house - a floor unit in the living room, in the front of the house, and a wall unit in their bedroom, in the back of the house. Even with both going, it’s pretty ridiculous. When my sister and I were kids, we would fight over space sitting on top of the floor unit in the living room.
Now I live in the Midwest, where central heating and cooling is mandatory. It is just WAY too cold in the winter to deal with that kind of bullshit.
Someone mentioned cross-ventilation as a means of cooling earlier. I know I’ve mentioned this before, but in Bulgaria, there is a folk belief that cross-ventilation (“techenie”) makes you sick. And when I say “folk belief” I mean “folk all believe it”. So it can be 38 degrees C but can you open the window? NOOOO. The techenie will make you sick! There are times when you just want to say “fuck cross-cultural understanding”. Those times include having people freak out because you’ve opened the window and the door when it’s forty freaking degrees because of the goddamn freaking techenie.
Our friend who was born and raised in Calgary has told us the same thing about New Zealand (where he has emigrated). It’s kind of funny hearing a western Canadian talking about how cold it is in winter in New Zealand, but we only have it cold outside here - our homes are all toasty. We have a theory that you could make a lot of money importing Canadian home-insulating/heating technology to New Zealand.
You can tell the new immigrants to Canada because they’re wearing coats buttoned all the way up when everyone else is in shorts and t-shirts. Five years later, they’re in shorts and t-shirts too. 
Could do with it today. Humid as fuck(for Dublin) and a whole 21 degrees C or around 70F :D, that’s quite up there for here.
I’ve never been in a private house with it. Almost all have central heating but not cooling.
I have a friend who was a SEAL and he said the toughest part of the training for many of 'em was they were always cold. The idea being that eventually they would get to a point where the temperature didn’t matter to them, which for him took a couple of weeks.
This isn’t even legal in my county. The tenant can do what they like with the controls, but the landlord is obligated to provide means to heat apartments to at least 68 degrees. If a resident called the county housing department and reported an interior temperature of 57 degrees, the landlord would be getting a citation.
I was quite surprised to learn of this law, as 68 degrees seems too comfortable to me (I figured they’d set the minimum at 64 or something), but it explains why our management company is so insistent that we report any problems with our heat to them immediately and then rushes out right away to repair it.
Coming up on 9p, it is currently 86, with humidity of about 70% and a dewpoint of 74. Feels like temperature is 93.
A/C is mandatory in Florida.