August made a valiant effort to continue the unusually cool and remarkably wet conditions of June and July and place a final exclamation point on one of the more enjoyable Oklahoma summers in recent memory. Unfortunately, that message was lost during the month’s final two weeks as the heat and dry weather of a normal Oklahoma summer found their way back to the state. According to preliminary data from the Oklahoma Mesonet, the mild first half and summery second half of the month combined to produce a statewide average temperature of 80.6 degrees, two-tenths of a degree above normal and the 57th coolest August since records began in 1895. Even that statistic was somewhat misleading, however, as the abundant moisture across eastern Oklahoma produced heat indices well into the triple-digits at times. The highest actual air temperature measured by the Mesonet was 105 degrees at several locations, certainly nothing out of the ordinary for August in Oklahoma. But the heat index often topped that mark, with Lane recorded a state-leading 112 degrees on August 8. The Mesonet recorded heat index values greater than 105 degrees 57 times during August. The climatological summer ended as the 26th coolest on record with a June-August average temperature of 78.7 degrees, nearly a degree below normal. The summer’s highest temperature, 107 degrees, was recorded by the Mesonet at several locations during June and July.
Only a late-month storm system saved Oklahoma from one of its top-five driest Augusts on record. There were a few locations that recorded generous moisture amounts. The Mesonet site at Porter led the state with 4.1 inches and several other stations across northern Oklahoma reported more than 3 inches, but 50 Mesonet stations recorded less than an inch for the entire month. Okemah and Putnam brought up the rear with a tenth of an inch in each of their gauges during August. The statewide average precipitation total of 1.4 inches was half of the normal total for August and the 12th driest since records began in 1895. West central Oklahoma suffered through its third driest August on record with an average of 0.3 inches. The summer as a whole was still wetter than normal, however, with a statewide average of 11.4 inches, 1.6 inches above normal to rank as the 34th wettest on record. North central Oklahoma had a near miraculous recovery from a disastrous first five months of the year with its 11th wettest June-August on record, 4.5 inches above normal.
The drought relief that was so prevalent from late May through July dwindled along with the rains during August. The month’s final U.S. Drought Monitor actually saw a slight increase in drought from the previous week as a result of the extended period of hot, dry weather. That final map portrayed approximately 49 percent of the state in at least severe drought, with 16 percent of that amount in the extreme-to-exceptional drought categories. The Drought Monitor’s intensity scale slides from moderate-severe-extreme-exceptional, with exceptional being the worst classification. The worst of the drought remained from southwestern through northwestern Oklahoma. Roughly 29 percent of the state, mostly across southeastern Oklahoma, was considered to be free of any abnormally dry conditions.
The September outlooks from the National Weather Service’s Climate Prediction Center (CPC) gave no indication of any temperature or precipitation anomalies for Oklahoma with both indicating equal odds for above-, below- or near-normal conditions. Unfortunately, given those uncertain conditions, CPC’s Monthly Drought Outlook for September indicated that drought was expected to either persist or intensify throughout the month. CPC’s seasonal outlooks for September-November point towards increased odds for below normal temperatures across the northwestern half of the state as well as above normal precipitation for all of Oklahoma. Those outlooks yield a U.S. Seasonal Drought Outlook with plenty of optimism for drought improvement or removal across much of the western two-thirds of the state by the end of November.