- 15 degrees is cold enough to need a sweater and maybe a jacket, unless you're right in the sun
- 25 degrees is just starting to warm up, but still uncomfortably cold.
- 30 degrees is a pleasant, comfortable temperature
- 35 degrees is hot enough to turn a fan on
- ...and if i had a window a/c by law, i would set it to 40 degrees, which is when it becomes justified to waste the energy.