July Rains Ease Drought

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. Summer returned in earnest beginning July 23, extending through the end of the month with highs in the upper 90s and 100s. July was the first month since September 2022 without a tornado report in the state. The preliminary count through the first seven months of the year stood at 63, already above the 1951-2022 annual average of 57.3 tornadoes with five months remaining.

The statewide average rainfall total for the month was 5.19 inches, 1.99 inches above normal and ranked as the 13th wettest July since records began in 1895. Nearly the entire state finished the month with a surplus, save for localized areas across far southern and northern Oklahoma where deficits of up to an inch were reported. The surplus rain totals from the eastern Panhandle through central Oklahoma were tremendous, however, at 3-7 inches above normal. Each of the 10 highest July rainfall totals were at Mesonet sites within that swath, from Woodward’s 9.71 inches to Norman’s 7.62 inches. The Panhandle, west central, and central Oklahoma all enjoyed top 10 wettest July rankings of sixth, third, and seventh, respectively. Sixty-one of the Mesonet’s 120 sites recorded at least 5 inches of rain for the month, and another 31 saw at least 4 inches. Burneyville in far south central Oklahoma reported the lowest total at 1.42 inches. Grandfield and Hollis also received less than two inches during July at 1.94 and 1.89 inches, respectively. The January-July statewide average of 22.83 inches was 0.81 inches above normal and ranked as the 43rd wettest such period on record.

The statewide average temperature for the month was 81 degrees, 0.9 degrees below normal and ranked as the 54th Coolest July since records began in 1895. Grandfield recorded the month’s highest temperature of 109 degrees on three separate days—July 18th, 19th, and 25th. The lowest reading of 55 degrees occurred at Eva and Kenton on July 2, and again at Eva on July 3. In addition to the 126 degrees at Pauls Valley, the Mesonet recorded heat index values of at least 110 degrees 346 times at its 120 sites during July. The highest recorded Oklahoma temperature of 2023 thus far was 113 degrees, recorded at Altus on June 28. The statewide average temperature for the first seven months of the year was 60.5 degrees, 0.5 degrees above normal and ranked as the 30th warmest January through July on record.

Drought coverage in Oklahoma dropped from 36% of the state at the end of June to about 18% at the end of July, leaving all but far southwestern and north central Oklahoma free of the climate hazard. Still, those regions remained in severe to extreme drought, exacerbated by longer-term deficits that stretch back to August 2021 and amplified by the summer of 2022’s disastrous flash drought. The Climate Prediction Center’s August outlooks show increased odds for above normal temperatures across the entire state, and above normal precipitation across far north central Oklahoma. CPC’s corresponding August drought outlook sees it being relieved—and partially eradicated—across the area of drought in northern Oklahoma, but persisting across far southwestern sections of the state. However, no new areas of drought are expected to develop through August.