Summer Heat Scarce During July

Oklahoma’s July was mild for the most part, and a bit wet for much of the state. Extreme temperatures—at least as read on the thermometer—were in short supply, but the pressure cooker heat due to high humidity seemed to be well stocked. Severe weather did strike sporadically through the month, mostly in the form of severe winds as is common to summer months in the Southern Plains. One tornado touched down near Yale in Payne County on July 7, an EF-1 twister that damaged homes and outbuildings. That brought 2021’s preliminary tornado total through July to 25 according to the National Weather Service. Oklahoma has averaged 50 tornadoes during the first seven months of the year from 1951-2020, with an annual average of 57.2 tornadoes.

The statewide average temperature as measured by the Oklahoma Mesonet finished at 79.5 degrees for the month, 2.4 degrees below normal and ranked as the 22nd coolest July since records began in 1895. A decade previous in July 2011, Oklahoma established its record highest statewide average monthly temperature at 89.2 degrees. The mark was not only the highest for any Oklahoma calendar month, but for any calendar month for any state since records began in 1895. Oklahoma’s lowest monthly average temperature for July, 76.4 degrees, came in both 1906 and 1950. Cherokee captured the highest reading for July 2021 at 103 degrees on the month’s final day, a somewhat tame extreme for an Oklahoma summer month. Oppressive heat was still present thanks to the generous rains that had fallen during the previous months. The Mesonet’s 120 sites hit triple digits only 62 times during July but reached a heat index of at least 105 degrees 639 times, and 110 degrees 99 times. The lowest recorded July temperature was 52 degrees from Eva on the 12th. The first seven months of the year were 1.8 degrees below normal with a statewide average of 58.2 degrees, the 26th coolest January-July period on record.

The statewide average rainfall total finished at 3.33 inches for the month, 0.13 inches above normal and ranked as the 47th wettest July since records began in 1895. Heavier rains fell across northeastern and southwestern sections of the state, with the southwest corner averaging 4.07 inches for the month, its 13th wettest July on record. Northeastern Oklahoma’s average of 5.22 inches ranked as the 22nd wettest on record. The Mesonet site at Bixby collected 9.38 inches to lead the state’s July rainfall tallies. Rains were not so plentiful across northern Oklahoma, where Buffalo’s 0.62 inches was July’s lowest total. A strip of Oklahoma from the northwest to the southeast experienced July rainfall deficits of over an inch, while most areas to either side of that strip enjoyed surpluses of 1-4 inches. The first seven months of the year remained on the wet side for nearly all of Oklahoma with a statewide average of 23.09 inches, 1.07 inches above normal and ranked as the 41st wettest January-July on record. Deficits of 3-6 inches were evident across north central and southeastern Oklahoma, as well as a localized region in the southwest. Surpluses of 4-8 inches were common from central through northeastern Oklahoma, ballooning to 12-14 inches across the far southeast.

Drought coverage remained low with only 1.13 percent of the state considered to be in drought at the end of July according to the U.S. Drought Monitor. A little over 7 percent of the state remained in abnormally dry conditions at the end of the month, mostly in far northwestern Oklahoma. That small area of moderate drought in the northwest is expected to remain through August according to the drought outlook from the Climate Prediction Center (CPC). CPC’s August temperature outlook indicates increased odds of below normal temperatures across the southeastern two-thirds of the state, but especially far southern Oklahoma. The precipitation outlook shows increased odds of above normal precipitation across southeastern Oklahoma and the far western Panhandle.