July Provides Summer Roller Coaster

Oklahomans enjoyed two stretches of mild weather during July, providing brief respites from the otherwise hot conditions and a tantalizing taste of fall weather to come. Two substantial cold fronts brought cooler temperatures and moisture, keeping high temperatures 10-15 degrees below normal during these periods. Oklahoma City experienced seven consecutive days with highs below 90 degrees from July 17-23, and 10 days overall during the month. Tulsa had 11 days below 90 degrees, including six consecutive days from July 17-22. Despite these cooler periods, there remained 15 days with triple-digit temperatures in the state, and heat index values exceeded 105 degrees on 14 days in July. There was sporadic severe weather throughout the month, with severe winds being the predominant hazard. Possibly the most significant event was eastern Oklahoma’s encounter with the remnants of Hurricane Beryl. The former Category 5 hurricane had diminished to a tropical depression as it passed over far southeastern Oklahoma and moved to the northeast, dropping 4-8 inches of rainfall across parts of McCurtain and Le Flore counties. No tornadoes were spotted in Oklahoma during July, and the preliminary total for the year remains at 110, according to National Weather Service reports.

Rainfall averaged across the state was 2.86 inches, 0.34 inches below the established normal, ranking as the 62nd-wettest July since records began in 1895. Oklahoma Mesonet totals ranged from 6.63 inches at Mt. Herman to 0.37 inches at Walters. The first two months of climatological summer, which runs from June 1 through Aug. 31, were also on the dry side, with a statewide average of 6.09 inches, 1.37 inches below normal, ranking as the 52nd-driest June-July on record. In a rare feat for Oklahoma, the Panhandle stations of Hooker and Goodwell led the period with 12.53 and 11.97 inches, respectively, while the federal site at the Guymon airport recorded 13.32 inches. The latter two readings are new records at those locations for the June-July period. The Mangum Mesonet site held the opposite side of that extreme with a scant 0.9 inches. The first seven months of the year were the 56th-wettest, with a statewide average of 21.4 inches, a deficit of 0.62 inches.

The statewide average temperature for the month was 81.1 degrees, 0.8 degrees below normal, ranking as the 54th-coolest July since records began in 1895. Temperatures ranged from 109 degrees at Buffalo on July 15 to 54 degrees at Bristow on July 19. The Mesonet’s 120 sites recorded a triple-digit temperature 484 times during the month, and heat index values of at least 105 degrees 908 times, culminating in a high heat index for the month of 118 degrees at Porter on Independence Day. The first two months of summer finished at one degree above normal, ranking as the 35th-warmest June-July on record in the state. The first seven months of the year were 1.9 degrees above normal at 61.9 degrees, the sixth-warmest such period on record.

The flash drought that had flirted with the state for several months struggled to flourish during July thanks to the milder weather and some timely rains, although a return of extreme heat at the end of the month fueled another intensification. Twenty-two percent of the state was considered in at least moderate drought at the end of July, according to the U.S. Drought Monitor, nearly all of which was in western and central Oklahoma. The Climate Prediction Center’s outlooks for August indicate increased odds of both above-normal temperatures and below-normal precipitation for all of Oklahoma, with drought expected to develop and persist across southwestern and central Oklahoma.