Born, raised and spent most my life up north on Long Island. I always loved the summers, didnt mind the winters either but I HATED the "in-between" fall and spring, when all it seemed to do was rain. Sometimes you could have a cold spring and half the time half the summer would be gone and we are big on ocean, lakes, swimming, boating, sometimes a couple day motorcycle trip and sometimes a motorcycle trip to the beach 2 hours away, needless to say we love summer and love heat.
So we moved to South Carolina, not on the ocean but near a huge 41 mile long lake called Lake Murray.
We get a solid 6 months of summer, at least 3 of those months day time highs are never less then 90 degrees. Its not half as humid as Long Island because after all, Long Island was surrounded by the ocean.
But either way could care less, some day we might even find ourselves back at the ocean/coast, humidity and all in South Carolina, which is where I am typing this from right now at a resort in N Myrtle beach, took a few days off, 3 hour car ride and we are at the beach.
We live near the central part of the state which is EXACTLY half way between the ocean and mountains, 2 hours either way.
Personally, reading your OP, if you hate heat that much, I dont know why you would move here, I mean, your moving south, its a fact of life. I love it and even just like I did the cold weather and snow, look at the heat as a challenge, heck, just a couple days before we drove here to the resort, I needed to get the lawn cut, I got out there with the two thermometers in our house saying it was 99 degrees outside, I look at it as a work out, even though its a self propelled mower. Ill cut the lawn at the hottest part of the day, though on a hot day like that, I will wait till later in the day where the yard is shaded. The flip side is winters are much more mild then up north, it can go down into the 20s and up to the 60s daytime. You can have an extended cold that lasts a week and you can have an extended 50 degree week.
One time in 15 years we got 6 inches of snow, schools were shut down for a week until it melted. *LOL*
There are some much cooler places, in the foothills of the mountains, both in NC and SC much more rural in the western part of each state though.
We also go to the mountains every year on our motorcycle but if you want to be a little closer, look into the Greenville SC area, also Spartanburg, it will be a little cooler but still HOT summers, if you go further west in the state its much like upstate NY, minus the huge amounts of snow.
)
I mean, either way, there is nothing wrong with heat if you like heat, there is nothing wrong with cold if you like cold. Its all a personal choice, Ill never go back to or would ever consider moving back to a New York climate. No way but that is me and my family, everyone is different. Always a way to hang out and keep cooler outside without special preparations and be comfortable.