Everyone has sleep comfort temps. Most sleep warm, so they lower evening temp. In the winter up north we keep sleeptime at 66. Here hvac runs less in the evening, so one can lower temp for little money

Why not turn it off at night and open the windows? Take advantage of the cooler air?

Wife turns it to 73, I turn it to 75. So depends on who walked by the thermostat last.

Similar to me only I keep mine at 76. Too cold at 75 for me.

74 degrees day and night but I use the ceiling fans to keep the air moving.

Some choose to open windows, those with severe allergies don’t. Our nighttime hvac run is 1.45 hours from 9pm to 5am.

Not sure why it bothers you people turn down their temp at night.

I didn’t say it bothered me. I am trying to find out the reason so many do it. Studies show that fresh air is healthier than air conditioned air.

The Health Benefits of Fresh Air - Physio Falmouth Plus

68 Degrees in the Summer
71 degrees in the Winter

It must be a California thing. I agree with 72 days and 67 nights.

Unless you wake up from that fresh air with severe breathing issues. Many as they age can no longer tolerate pollen. This year in our screened lanai everything was covered in yellow pollen. Our screen is pet quality, I can only imagine what a common screen in a window would allow in.

Bonus when we both worked wore masks for 16 hour day, total air exchange every 15-20 minutes. I miss those days where could breathe without coughing and sneezing. Pollen in FL seems there isn’t a break, just degrees of how heavy or light it is

We're currently set at 80 degrees, day and night, fans in living room and bedroom running. Our (recently former) summer home only had a/c in the bedroom, thick stone walls 400 years old, so it kept heat out. And it was dry there. I think we gradually got used to warmer temps, because we used to run 78 at day and 74 at night here.

72-73 during the day.
65 at night with ceiling fan on medium, in the bedroom.