September scorches Oklahoma, then delivers a splash of hope

The drought and relentless heat that plagued Oklahoma for months reached a crescendo during September before a rare guest came calling from the Pacific Ocean during the month’s final two days. Moisture from the remnants of Hurricane Polo spread across the High Plains and interacted with a large upper-level trough to help bring long-awaited, widespread rain to Oklahoma. By then, however, the damage was done. The month shattered Oklahoma’s previous September temperature record by nearly 3 degrees, while extreme and exceptional drought expanded to their greatest combined coverage since February 2023. 

September shatters heat records

September’s statewide average temperature of 82.8 degrees was 9.9 degrees above normal, shattering the previous September record of 80.1 degrees set in 1931 by 2.7 degrees. Talihina and Waurika led the state with 19 days of temperatures reaching at least 100 degrees. Grandfield recorded the month’s highest temperature, 109 degrees on Sept. 12, while Clayton registered the highest heat index, 116 degrees on Sept. 6. The month’s lowest temperature was 52 degrees at Eva on Sept. 28.

The heat also took a toll on Oklahoma’s record books. A preliminary review of 21 long-term station histories identified at least 216 daily temperature records set or tied during September, including 101 record highs and 115 record warm lows. Combined with August’s tally, that brought the two-month total to at least 356 daily heat records set or tied. Oklahoma City broke eight daily high or warm-low records and tied five others during September, while Tulsa broke five and tied five. Tulsa’s low of 83 degrees on Sept. 9 was its warmest daily minimum ever recorded in September dating back to 1905, surpassing the previous record of 82 degrees.

September’s extraordinary warmth extended an already historic stretch of heat. Oklahoma’s January–September average temperature reached 68.7 degrees, 4.9 degrees above normal, barreling past the previous record of 67.1 degrees set in 2012 by 1.6 degrees. Oklahoma’s warmest February, March and September on record have all occurred in 2026. 

Drought deepens under record heat

September’s record heat accelerated Oklahoma’s drought, intensifying the prolonged dryness in western Oklahoma and worsening the drought that had spread rapidly across central and eastern sections during summer. Nearly the entire state remained in drought, with extreme and exceptional drought expanding from 41% of Oklahoma at the beginning of September to 55% by month’s end, its greatest coverage since February 2023. Exceptional drought, the U.S. Drought Monitor’s most intense category, nearly doubled from 12% to 24%, encompassing substantial portions of western Oklahoma and parts of the south. That was its greatest extent since October 2022. The month’s final Drought Monitor assessment preceded much of the rain that arrived during September’s final two days.

The drought’s toll extended well beyond the map. Farmers and ranchers reported depleted pastures, drying ponds and creeks, early hay feeding and livestock sales. Some producers moved cattle to pastures with remaining water, while others reported animals becoming trapped in pond mud. Producers also reported delayed wheat planting, sharply reduced hay production and poor soybean yield prospects. Reservoir levels reflected the prolonged dryness, with Lugert-Altus about 23 feet below normal pool elevation and Ellsworth about 10 feet short late in the month. Heightened wildfire danger prompted burn bans covering at least 61 of Oklahoma’s 77 counties during September.

September flips the rainfall script

Repeated plumes of subtropical moisture — including a boost from Polo — gave the western Panhandle the rare honor of leading Oklahoma’s monthly rainfall totals. Kenton earned the top nod with 7.70 inches, while Boise City was close behind with 7.35 inches. Norman had the lowest total at 0.15 inches. The normally dry Panhandle soaked up its fifth-wettest September, while the usually rain-rich southeast scraped together just 0.89 inches for its eighth-driest. The statewide average rainfall total was 2.28 inches, 1.04 inches below normal, ranking the month as Oklahoma’s 42nd-driest September since records began in 1895.

Oklahoma still had plenty of catching up to do. January through September rainfall averaged 22.58 inches statewide, 5.99 inches below normal, marking the state’s 28th-driest first nine months of the year since 1895. Rain continued into October, with several additional inches falling in parts of southern Oklahoma during the early morning hours of Oct. 1, after the cutoff for September’s totals.

September by the numbers

• Statewide average temperature: 82.8°F, 9.9°F above normal — the warmest September since records began in 1895
• Temperature extremes: High of 109°F at Grandfield on Sept. 12; low of 52°F at Eva on Sept. 28
• Highest heat index: 116°F at Clayton on Sept. 6
• Warmest and coolest locations: Highest monthly average, 86.7°F at Grandfield; lowest, 73.8°F at Kenton
• Statewide average precipitation: 2.28 inches, 1.04 inches below normal — 42nd-driest September since 1895
• Rainfall extremes: High of 7.70 inches at Kenton; low of 0.15 inches at Norman

October offers hope for drought relief

The Climate Prediction Center favors above-normal rainfall across southern Oklahoma, with equal chances of above-, near- or below-normal precipitation farther north. CPC notes that the southern storm track associated with strong El Niño events is already beginning to take shape, helping support the wetter outlook. Temperature odds are evenly divided among the three categories across most of the state, with above-normal temperatures favored in parts of the Panhandle. The monthly drought outlook calls for widespread improvement across Oklahoma, although drought is expected to remain across much of the state at month’s end.