Warm December Caps Warm 2023

December was unusually warm across all of Oklahoma, and uncommonly wet across the northwestern third. A prolonged absence of Arctic air led to the state’s fourth warmest December since records began in 1895, and contributed to 2023’s rank as the 10th warmest calendar year. The month continued a string of Decembers with above normal temperatures in the last decade. The Decembers of 2019 and 2015 ranked as the 13th and sixth warmest across the state, respectively. In 2021, we witnessed an unprecedented event as December marked the pinnacle of extremes, finishing over 10 degrees above the normal temperature. This surpassed the previous record for the warmest December, set in 1933, by more than 5 degrees. The only outlier in the past 10 years was December 2016, which stood at half a degree below normal. December moisture surpluses amounted to 200-400% of normal, while deficits reigned to the southeast. A storm system from Dec. 13-15 deposited 2-4 inches of snow across the Panhandle, with other wintry weather resulting in mostly light totals. Severe weather remained almost entirely absent in December, with no confirmed tornadoes. The preliminary tornado total for 2023 stands at 74, significantly higher than the 1950-2022 average of 57.3 twisters.

The statewide average temperature for the month concluded at 44.6 degrees, surpassing the normal by 4.5 degrees. December's highest temperature, reaching 80 degrees, was recorded in Beaver on Dec. 7 and again in Burneyville the following day. Kenton experienced the month's lowest temperature, dropping to 10 degrees on the second. In 2023, the statewide average temperature stood at 62 degrees, exceeding the normal by 1.6 degrees. The highest recorded temperature for 2023 was 114 degrees in Grandfield on Aug. 17, while the lowest was minus one degree in Kenton on Feb. 17.

The statewide average precipitation total for the month reached 2.62 inches, exceeding the normal by 0.51 inches and ranking as the 25th wettest December since records began in 1895. The western half of the state experienced a significant surplus of 1-3 inches, while the eastern half largely faced deficits of around an inch. The Panhandle enjoyed its third wettest December on record, boasting an average surplus of 1.71 inches, and the west-central region's surplus of 2.1 inches ranked their month as the seventh wettest. The southeast fared the worst, marking their 43rd driest December with a deficit of 1.89 inches. The Mesonet site at Cookson led the state with 4.99 inches, and another 34 sites recorded at least 3 inches for the month. Kenton brought up the rear with 0.83 inches. In 2023, Oklahoma finished as the 48th wettest year on record, with a statewide average of 36.23 inches, falling short of normal by 0.13 inches. The Panhandle once again performed exceptionally well with an average of 27.12 inches, surpassing the normal by 6.97 inches and ranking as their sixth wettest year on record. The Mt. Herman Mesonet site led 2023's totals at 65.72 inches, while Boise City had the lowest total with 16.87 inches.

Drought coverage in the state decreased from 34% at the end of November to 22% at the close of December, as reported by the U.S. Drought Monitor. During the same period, the extent of severe and extreme drought reduced from 11% to 3%. The January outlooks from the Climate Prediction Center indicate increased odds of below-normal temperatures across all regions except far southeastern Oklahoma, with above-normal precipitation expected across the entire state. Despite the potential for increased precipitation, CPC's drought outlook anticipates persisting drought conditions through January in areas where it currently exists. The CPC predicts El Niño to continue throughout the winter before transitioning to neutral conditions in the spring. This ocean-atmosphere coupling phenomenon can bring cool and wet conditions to the Southern Tier of the United States, including Oklahoma, during the cool season.