In what could best be described as a climatological anomaly on steroids, Oklahoma soared to its warmest December on record, besting the previous mark by more than 5 degrees. It was a remarkable display of muscle by Mother Nature that saw the statewide average temperature finish more than 10 degrees above normal as measured by the Oklahoma Mesonet. For some perspective, the next nine warmest Decembers all reside within 2 degrees of each other. No other calendar month in Oklahoma has such a large spread between the top two marks. May has the next largest difference at 1.2 degrees. December 2021 also became the fourth warmest climatological winter month since statewide records began in 1895, just a few tenths of a degree behind the top spot in February 1954. The cool season heat wave was a culmination of warmer and drier than normal weather that began in earnest in mid-August and continued largely uninterrupted right up until the ball dropped on 2022. An arctic cold front arrived just before midnight on New Year’s Eve and brought an abrupt end to the spring-like temperatures with snow, ice, freezing rain, and bitterly cold air.
A profound lack of precipitation combined with the unusual warmth to propel drought forward in both coverage and intensity at speeds often reserved for the summer months. According to the U.S. Drought Monitor, drought increased from 61% of the state at the end of November to 90% at the end of December. The amount of severe and extreme drought increased from 16% to over 72% during the month. The Drought Monitor’s intensity scale slides from moderate-severe-extreme-exceptional, with exceptional being the worst classification. The addition of strong winds to the equation resulted in numerous days with dangerous wildfire conditions. Widespread non-thunderstorm wind gusts of 60-80 mph across western Oklahoma on Dec. 15 fanned flames into the western sides of Guymon, forcing evacuations. Dust storms closed roads in the Panhandle due to poor visibility, producing images right out of the Dust Bowl era.
The statewide average temperature finished at 50.4 degrees, 10.3 degrees above normal and easily surpassed the previous top mark of 45.1 degrees from both 1931 and 1965. Many individual locations across the state set similar temperature records. Oklahoma City’s 50.7 degrees topped its previous record of 48.7 degrees in 1965, and Tulsa’s 52.2 degrees eclipsed 1931’s 47.3 degrees. Oklahoma City and Tulsa’s records date back to 1890 and 1905, respectively. The Mesonet recorded highs of at least 70 degrees on 25 separate days in December, and at least 80 degrees on 13 days. The month’s highest reading of 89 degrees at Grandfield on the 24th is the highest December temperature recorded by the Mesonet since its temperature records began in 1997, and ninth highest compared to longer running cooperative network data that extends back to the early 1870s. Tops is the 92 degrees reported by Ardmore back on Dec. 30, 1951. The coldest reading of December 2021 was 3 degrees at Camargo on the 19th. The warm December vaulted 2021 up to a final ranking of 19th warmest at 61 degrees, 0.6 degrees above normal. 2021’s highest temperature was 107 degrees at Eva on June 23, and the lowest of minus 22 degrees was reported at Kenton on Feb. 15.
The month’s statewide average precipitation total ended at 0.95 inches, 1.16 inches below normal and ranked as the 34th driest December on record. That statistic is bolstered by decent moisture across far eastern Oklahoma, but most of the western two-thirds of the state experienced an alarming lack of precipitation. Nineteen of the Mesonet’s 120 sites recorded no precipitation for the month, and an additional 33 received a quarter-inch or less. The Panhandle suffered its driest December on record with no precipitation for the month, west central had its third driest at 0.01 inches on average, and north central’s 0.06 inches ranked as their fifth driest. Many locations in Oklahoma had not received more than a tenth of an inch of rain in a single day for more than two months. Some sites in the Panhandle had gone without measurable moisture since Oct. 10. The Mesonet site at Cookson led the state with 4.26 inches, while 11 other sites across eastern Oklahoma enjoyed more than 3 inches. 2021 finished as the 63rd driest year on record with a statewide average of 33.63 inches, 2.73 inches below normal. Kenton’s 12.9 inches was the Mesonet’s lowest total during 2021, while the site at Mt. Herman won the top prize with 61.13 inches.
Chances for significant drought relief appear slim according to the Climate Prediction Center’s January precipitation outlook, which indicates increased odds of below normal precipitation across the western two-thirds of the state. Their temperature outlook for January shows increased odds of above normal temperatures in far southwestern Oklahoma and the western Panhandle. CPC’s January drought outlook calls for the existing drought in Oklahoma to either persist or intensify through January. No further spread is expected, however.