Nice chart you made. If curious, you can get those charts for some places online too. Weather underground is good, but the scale is too small for the year so you have to do it month by month for a good picture. For example, here it is for us in January and you can scroll forward by month from there.
http://www.wunderground.com/history/air ... atename=NAYou can also pull a good one up here for the year, but unfortunately they stopped reporting the station nearest me, but here's a close one:
http://www.hprcc.unl.edu/stations/index ... _id=055446
Click for full size:
http://www.summitpost.org/images/original/349404.bmpI still like yours better.