I'm not big on AC. I much much prefer open windows. My rule of thumb is when it gets to be above 88 outside. I have no idea what this is inside. Our living room is fairly well shaded by some big trees, so I am sure that helps.
I'm in SE PA, where we probably see 20-30 88 plus days a summer.
We let it get up to about 90 last year. We're in and out all day long, so once you get used to the outside, it's okay if the inside is hotter. We've got ceiling fans in every room we use, including the kitchen and our master bathroom, and that helps a lot. We open windows a lot at night to help it cool down, since I can't sleep if it's too hot. It also helps my son to sleep to hear the night sounds outside.
I don't know if we'll let it get that hot this year or not since DH works from home and he has to close his door when he works to quieten the noise from the kids. His office gets hotter than the rest of the house because of all of the computer equipment. His saving grace is that he can pretty much work in whatever attire, so a lot of times that's shorts and a t-shirt (or no shirt).
I can stay pretty comfortable in our house a long as the daytime high stays below 85. In our climate in an average year that may only be 5 days per year. I'd had lived here for 5 year before it ever broke 90.
We have central air and use it, but I don't think I would have had it installed for the little amount we use it.
I'm not a person who enjoys the heat, in fact I dread it (although I wouldn't mind some sunshine and a few days at 75 right now!). Luckily, I live in Oregon so it doesn't get too hot very often. To be honest, I have never lived in a house with central AC as our houses have always been old (1950's and earlier) so I wouldn't even know what it is like. Last summer my mom did buy us a large window unit because she insisted we were going to roast. We used it once or twice.
Does your DH work in an air conditioned office? I know that I had even less tolerance for heat when I worked full time in a cool office. My body would regulate to my work environment and then I would get a total shock going outside/home. If he does, I would highly recommend the cool shower. That always really helped me.
I'm in Florida also, I have lived here a year after spending my entire life in Rhode Island. Let me just say, my a/c never goes off. It has been set at 75 all winter and in the summer, it gets turned down to about 71. I hate the heat and humidity. I have ceiling fans as well in the new apartment and I do use them. I don't care how high my electric bill gets. I need to breathe, I have severe asthma and if I can't control my asthma that turns into a hospitalization.. I don't need one of those, the last time I went in, it was $20K for 5 days. I would rather pay $100+ a month for a/c than 20K for 5 days of hospitalization several times a year (especially now that I'm self-employed and can't find health insurance that will accept me).
it needs to be 85 and HUMID in the house before we turn it on. Usually, it is only on at night when we sleep and we turn it on get the room cold and turn it off... but this is the household that usually keeps the heat at 58 in the winter.
I try not to turn ours on until it reaches 80, but that only works if dh is not home. He starts to go crazy if it gets over 75. Sometimes I get upset that we have to deal with the heat all day, and then he comes home and it gets turned on. At least I can keep it from running all day long this way.
It really depends on climate. If it hits 80 degrees in our house in Illinois, we're in our underwear, sweating, cranky, and my asthma is acting up. It is just so humid here. But when we visited our friends in Las Vegas in June, their thermostat was set at 80, and it felt fine.
Well never, and we live in australia so temps over 100. We just shut the windows up early to keep the heat out and use a small fan, it was hard the first year without an ac, but its not a big deal. We are saving to get a small energy efficiant reverse cycle in the bedroom for the baby, but that is more for heating at night during winter. But again it depends on humidity levels, when its humid i sure wish i had one, esspecially as this summer i was pregnant.