One thing I have noticed, and put it down to trying to achieve MPG, is less efficient aircon.
My old Xantias and my IS200 had climate control and if I dialled in 21C in summer they got down to 21 or 22 and maintained it. Checked on a strategically placed accurate digital thermo, placed out of the sun.
My 2007, 2009 and 2013 Civics, if I dial in 21C it doesn't get below 25/26C and doesn't feel cool inside. The answer is to dial in 19C or lower depending on the sun's strength and manually turn up the fan speed.
All 3 Civics from new so not an old system.
If you really want to kill the aircon hit the Eco button. I did that once and watched the temp in summer, with 21C set, rise above 30C.