Oklahoma Record Maximums In Sharp Decline Since The 1930s

http://cdiac.ornl.gov/ftp/ushcn_daily/state34_OK.txt.gz

The two biggest years for Oklahoma all-time record maximum temperatures were 1936 and 1956. By contrast, 2011 was not much above average.

All years which share a record maximum get counted in the graph above, so there is no bias in either direction.