We all just dress in endless layers.
I live in Fortaleza, Brazil. Temperatures here are very stable along the whole year (78F - 90F, it rarely falls out of this interval).
I'm not advocating this no-AC model as a general solution though. I'm aware we're a bit lucky here. I used to live in Sao Paulo and temperatures vary more wildly there, sometimes within a single day.
And the temperature gradient I've mentioned is correct. No noticeable changes along the whole year, I'm sorry.
It does sound kind of unpleasant, but I imagine you get used to it.
But it changes the way you live. Compared with lives of friends from Europe, I notice that theirs has a bit more of a "structure" and predictability. E.g., hang out more in the summer, doing more reading and writing more in the winter.
I think I would enjoy that. Of course I could plan my life based in months instead of seasons, but it's not the same, especially considering that people around me wouldn't be following that same plan.
Not enough rain / sunny and 50 F
Sunny and 70F; green plants
Sunny and 90-105 F; brown plants
Red Skies, ??? F; black plants / red embers
I've lived in cities where we experience anything between below zero to 120F throughout the year. I couldn't imagine not having AC/Heating in those areas even with more efficient ventilation/insulation.