My Dad moved (with the rest of us) from Montreal to Los Angeles when he was 46 years old. He’s been living in L.A. now for 30 some years. He has said that he would no longer be able to tolerate “real” winter conditions, even for a short visit. That’s how much he has adapted to the SoCal climate.
Florida to Connecticut also at ~29. Same experience.
I grew up in Central New York. Been living in SoCal for 25 years and I still think it is too bloody hot here. I am the crazy American you see in Denmark in January wearing a windbreaker, saying “What? It’s not that cold.” (Yes, I really have done that.) I love the 4 seasons in the Northeast. Why am I in southern California? sigh
Moved from Oregon to Houston, and yes I laugh at the Houstonians who get all upset when the weather stays in the 50’s for a few weeks. They complain about how long and hot the summers are, and then when we get a couple of months of cooler weather, they freak out about how cold it is.
I love the climate in Houston though, and don’t mind the heat in the summer. The winters are awesome though 
A related GQ thread. The last two posts especially are the sort of anecdotes you seem to be looking for.
I moved from the Great Lakes area of northern Indiana to middle Tennessee in my early thirties. I would resist going back to the northern climate in the winter with all of my might.
I do best in a climate where you run your AC for more months than your heat. When I retire, I plan to move to an even warmer climate, probably in Texas or New Mexico.
I grew up in Philadelphia, but Mr. Ko and I moved around the country a lot. We have always lived in reasonably temperate climates with four well delineated seasons – the Pacific Northwest, for the longest. Our last move was to the Desert Southwest and have been here about five years. I whined about the heat for the first two, but I’m pretty well acclimated.
Which is to say that now when I visit my family back east, I whine about the cold and the humidity. 
I grew up in a hot and humid environment on the Gulf Coast. Then at age 32 I moved to a hot and dry environment, the Sonoran Desert. At first it felt so weirdly dry that I was putting on lotion about 10 times a day, and it felt like no matter how many cups of water I drank, I was always dehydrated.
Now I’ve lived in the desert over 10 years and when the humidity goes over 30% it drives me crazy and the air feels so thick! I can’t believe I lived most of my life with over 90% humidity.
I lived in various hot and humid places for most of my life and then moved to the mountains in Idaho four years ago, in August.
After about a week my body sort of said, “Aaaaaaah!” and relaxed and then winter came and I loved it. Still do. In mid October I get really cold for a week or so and then it’s like somebody throws a switch and I’m fine. Dry and cold? Fine by me. I have more energy in the winter than the summer! Is there an opposite version of SAD? Natives up here bitch about the heat when it gets above 80F. With next to no humidity. That is not hot. I still laugh at them, along with my friends who came here from Mississippi some years ago.
I have sworn off heat and humidity forever. I could deal with cooler and humid, as in the Pacific Northwest, but there’s no way I’m going back south. Besides, I love snow. I would miss it!
I grew up outside Chicago, and hadn’t lived anywhere without 4 seasons until a couple of years ago.
Went from cold and wet to hot and dry.
My sweetie was born and raised right here in desert-ville.
But I’m the first one to turn off the AC when it gets cooler, first one to don a jacket. 
I’m trying to get him to recognize the awesome comfort and coziness that comes from being bundled up when it’s chilly; he just waits until he’s actually COLD before thinking of a coat. Pfft.
I was stationed in Okinawa and then moved to Hawaii. I hated the weather in Okinawa, it was so humid. Hawaii was nicer because of the gentle winds. I’ve lived in Central AZ for over 10 years now. Currently, I’m in Houston and its soooo cold! Bill makes fun of me because I’m wearing sweatshirts under my jacket. I’ve learned that a wet cold is much colder than a dry cold.
This is why I am never moving away from SoCal. I’m afraid I don’t have the ability to acclimate to colder climates. When it gets to 55 or below, I am FREEZING to death. On winter mornings when I’m driving to work and its 40, I can barely function. My hands hurt from inserting the key into the ignition, I have to blast the heater at max for 30 mins. My feet and legs are cold, I’m huddled in a giant jacket, and I wear socks all day and night. I loathe the cold
Reverse this and it describes how I feel about heat and humidity! Anything over 80 makes me unhappy. And I work a lot outside in the summer, so it’s not like I get to be insulated in climate-controlled environments.
It’s a relatively balmy 23 degrees out right now and I was outside barefoot in the yard for about 5 minutes earlier this morning. 
Forty degrees is light sweats weather, nice for a brisk walk. As soon as it gets light, I’m driving my dogs to the nearby lake beach for a run. The only thing that would make it better would be fresh snow. Mmmm. Snow.
I grew up near Detroit, with all of that miserable weather. I moved to the Phoenix area in July of 2007. Like many other posters, I acclimated to my new climate and start getting cold at much higher temperatures.
Michiganders like to talk about the dry heat here and how “It’s way worse in Michigan when it’s 90 degrees and humid!” No, fuck you, I’ll take 90 and humid over 117 and dry any day. When it’s 117 it becomes physically painful for me to be outside for more than 5 minutes; that never happened during Michigan summers.
Born, raised & lived in Florida (Jacksonville, then Fort Lauderdale) for the first 35 years of my life.
I moved to NW NJ in 1995 with 20 pairs of sandals and no winter coat. 
I thought I was going to die my first winter. My fiance at the time was a native of the area and kept the thermostat at like 60 degrees. He’d leave the house, and I’d flip that sucker up until about an hour before he was due home. lol
Now my thermostat isn’t set much higher, and I do just fine, but it took a few years of adaptation.
And yes, I did buy a winter coat that first year
UT
Born in the Rocky Mountains. After a few years in northwestern Arkansas, grew up mostly in the mild-to-freezing South Plains of West Texas. Moved to Thailand in my 20s. Then spent a brief time back in the mild climate of Albuquerque (but the winter was pretty chilly), then 2-1/2 years in the tropical paradise of Hawaii and finally back to Thailand – all of that in my 30s, and I’ve been here ever since.
I’ve acclimated pretty well. Can’t take cold weather anymore, uh-uh, not for me. Although sometimes at the height of our hot season, I wonder if it might not be worth a try. But then the monsoons rains return, and I think: “Naw.”
Wow. It’s about 25 degrees outside. I’ve been to church and back, and done some shopping, and haven’t even put on a jacket.
You and I will never meet in person
You either!
Grew up in the south and lived in various southern states for school until time for residency in my mid twenties. I ended up at a great program but VERY far north – I hated the cold winters but the hardest adjustment was learning to drive in the snow/ice. I think year to year I just consciously chose to block out how bathe winters were.
Now that I am back in the south I tolerate the cold better but when we get the yearly storm of a couple inches or so that shuts down everything I am actually more reluctant to drive because really most people here don’t know how to drive in winter weather.
Lived the first 32 years of my life in northern Maine. Moved to Georgia 23 years ago and have never gotten used to the heat and humidity in the summer. I’d go back to Maine in a second.