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.
The Oklahoma Mesonet’s temperature data tell the story of a dry and unusually warm November, but there was actually a good dose of winter during the month, as well as a nice measure of rain at the end. The state’s first significant wintry precipitation of the season fell in the state on Thanksgiving Weekend across the northwestern half. Totals generally ranged between 2-4 inches, but a swath of 4-6 inches occurred across far northwestern Oklahoma and the eastern Panhandle. Isolated totals of 8-9 inches were reported in parts of Beaver and Harper counties.
The flash drought that had plagued the southwestern half of Oklahoma since mid-July appeared poised to explode across the entire state during October. As it began its northward advance, however, assistance arrived in the form of three distinct storm systems that not only halted the drought's advance but reversed its course. The first storm originated from the Tropical Pacific off the West Coast of Mexico.
Flash drought continued to advance and intensify across the southwestern half of Oklahoma during September, aided by scorching hot weather and a prolonged dry spell that had stretched to more than 60 days in some areas. While there was some relief during September from the dry and hot conditions—the weather cooled considerably during the month’s second week to go along with heavy rains—summer weather returned soon thereafter for the remainder of the month.
Oklahoma tried its best Al Pacino impression from “The Godfather Part III” during August, being pulled back into drought after nearly escaping its clutches completely thanks to record moisture the previous three months. The heat and dry weather roared back with a vengeance, however, and flash drought erupted for the second consecutive summer. Only 13% of the state was in drought on Aug. 8 according to the U.S. Drought Monitor, contained entirely in small patches across far southwestern and north central Oklahoma.
The unusually wet and mild weather Oklahoma enjoyed through much of May and June continued into July, providing the state with uncharacteristic summertime drought relief. The Southern Plains heat dome still managed to meander its way over Oklahoma for short periods, however, basting the state in intense heat and stifling humidity. The Oklahoma Mesonet site at Pauls Valley reached a network-record heat index of 126 degrees on July 13, besting the previous record of 125 degrees from Calvin back on Aug. 9, 1999. The Mesonet’s heat index records date back to 1997.
June took up the slack for May’s relatively tame severe weather output—at least by Oklahoma’s standards—with 10 tornadoes and two possible derechos that left over half of a million Oklahomans without power. While storms threatened the state throughout the month, the most intense severe weather was concentrated within just a few days from June 15–18 thanks to two powerful storms systems, both aided by an unusually strong jet stream overhead.
Central Oklahoma has often been characterized as a haven for tornadoes, with some of that perception based in reality—and myth. There has been nothing mythical about that reputation in 2023, however. At least 11 tornadoes touched down in central Oklahoma on May 11, adding to persistent tornadic activity in that region during the previous 4 months of the year. Through just 5 months, the central Oklahoma counties of Cleveland and McClain broke their records for number of tornadoes in a calendar year with preliminary totals of 13 and 11, respectively.
Drought relief and severe weather topped April’s weather headlines with a parched northwest Oklahoma seeing its first significant moisture in months and central Oklahoma enduring a tornado outbreak. Eighteen tornadoes touched down on April 19, a day when severe weather was thought to be limited by a warm atmospheric lid above the surface. High temperatures over 90 degrees combined with a potent dryline to break that lid and initiate the storms that would eventually spawn the twisters.
Oklahoma’s oddly persistent caste-like rainfall pattern—with those to the north and west of Interstate 44 seeing near-record dryness and those to the south and east experiencing abundance—continued during March. Rainfall totals to the northwest of I-44 were generally a half-inch or less, while amounts of 5-8 inches were quite common to the southeast. Ten Oklahoma Mesonet sites in far northwest Oklahoma failed to record more than a tenth of an inch of rain for the month, with another 17 stuck below the quarter-inch line on the rain gauge.