The first four years the stock show was held (1906-1910) revealed that the average temperature during the event was 43.6 degrees, 12.9 degrees above normal for that time of year. In fact, 1909 was the warmest stock show on record with a departure from normal of 16.0 degrees.
Cold spells were few and far between. Extreme departures from normal only lasted a year or two at a time. From 1962-1963 the average temperature was 8.6 degrees, 20.4 degrees below normal. This was the coldest consecutive stretch on record.
To summarize, the mean temperature during the National Western Stock Show from 1906-2003 is 31.8 degrees. The normal during the same period is 29.1 degrees, giving a departure from normal of +2.7 degrees. This indicates that the mean temperature is warmer than normal during the National Western Stock Show, disproving the perception that it's always cold when compared to normal.
Below is a chart of yearly observed and climatological normal temperatures and there departure from normal during the National Western Stock Show since 1906.