While there are websites like www.weatherunderground.com that provide historical data about temperatures, rainfall etc, is there a repository of historical ATIS information?
The following is one starting point:
http://lwf.ncdc.noaa.gov/oa/climate/stationlocator.html
The following lists the metars for KMSN for 1 August 04
http://www.wunderground.com/history/airport/KMSN/2004/8/1/DailyHistory.html