Exceptional drought (D4) coverage on the U.S. Drought Monitor for the week ending September 22, 2026, is shaped primarily by persistent dry conditions and flash drought intensification across the Southern Plains. As of the September 17 release (data valid September 15), Oklahoma shows the most notable expansion, with D4 now affecting 16.59% of the state—its highest level yet—while Texas holds 3.6% in D4 amid broader severe-to-extreme drought across 81% of the state. Limited September rainfall, above-normal temperatures, and minimal streamflow and soil moisture in these regions have driven the recent degradation, contrasting with improvements in the Midwest and stability in western exceptional drought pockets such as southern Idaho and northern Nevada. The next USDM map, scheduled for release September 24 with data through September 22, will incorporate any late-week precipitation; current forecasts indicate continued dryness for much of Texas, Oklahoma, and the Lower Mississippi Valley through at least mid-week, with limited relief expected before the valid period ends. Traders should monitor short-term rainfall totals and the National Weather Service Climate Prediction Center outlooks for any shifts that could alter D4 boundaries before the cutoff.