Stations with long term records show that Oklahoma maximum and minimum temperatures have been in decline since 1900.
The hottest year (by far) was 1954.
Interesting to note that Oklahoma minimum temperatures in 2011 were in the bottom ten, including the coldest Oklahoma temperature ever recorded, -31F on February 10, 2011.
Feb 10, 2011
The town of Bartlesville, Oklahoma reported a morning low of -28 — yes, that’s Oklahoma, not Minnesota — at their official station, which would set the all-time record low temperature for the entire state of Oklahoma. (Their previous record was -27 set in Vinita, Okla. in 1905 and Watts, Okla. in 1930.) NOAA says they have to inspect the equipment to make sure it’s in proper working order so at this point the record is preliminary.
But! There is a second contender. A non-FAA station in Nowata, Okla. reported a temperature of -30.5 degrees. NOAA is checking that one too. Suffice to say, there is pretty good evidence that Oklahoma has a new state record and Vinita and Watts are going to have try harder to get back into the books.