Meeker, Oklahoma is the closest USHCN station to Oklahoma City. Measured summer maximum temperatures have been in steep decline since they started keeping records. Prior to 1950, they had five summers which averaged higher than 98F. Since 1950, there have only been two summers over 98F.
I doubt that you will see this information in any NOAA reports. It doesn’t fit the agenda.
Hansen wrote this in 1999 :
Empirical evidence does not lend much support to the notion that climate is headed precipitately toward more extreme heat and drought. The drought of 1999 covered a smaller area than the 1988 drought, when the Mississippi almost dried up. And 1988 was a temporary inconvenience as compared with repeated droughts during the 1930s “Dust Bowl” that caused an exodus from the prairies, as chronicled in Steinbeck’s Grapes of Wrath.