Guitar Tuning and Temperature Changes

This is a 1.81 minute video response from Nick Greathouse on Nov 1st, 2008

Question:

"scopexs asks, "I have been wondering about tuning and temperature. In my area it is cold in the morning and I will sometimes tune my guitar and play for a little relaxation to start my day. Later the temperature will get warmer and I have wondered if I should wait to tune my guitar. I thinking about expansion and contraction and the effect on tuning the guitar. It seems that in the later part of the day I end up having to retune the guitar down to get the proper tuning. Should I wait until the temperature levels out to tune? Thanks for you help....""