I was at the track one day and thought I'd blown a cylinder or something... I couldn't do anything under a 12-second quarter-mile and it was driving me nuts pass after pass.. I got home and started reading about atmospheric pressure and got a measurement from the track that day and it said I was supposed to be doing 12 seconds or more..
As long as the car hooks, average hot and humid summer day vs average cool fall day is usually about 2 tenth average difference at the same track. Head wind or tail wind obviously plays a part too.
Usually my track is hot and humid with a slight head wind on days I'm able to make it down there for a pass.... usually.. LOL