39° F outside my house right now, and we are supposed to get 12"-18" of snow over night. Pretty normal weather for early spring here, but it has been a bit warmer than normal. Overnight lows have been almost above freezing which usually doesn't happen until mid May.
If the temps in my office start to approach 70, I just crack a window, and that cools it down. In the summer time I just leave the windows open. There are usually only a few weeks where temps get into the 80s, so not having to run A/C definitely helps with keeping utility costs down.