Observed precipitation from National Weather Service climatological reports on September 21, 2026, forms the core driver of trader consensus for this market. Showers and steady rain fell across the Midwest to Northeast corridor, with measurable amounts including 0.64 inches in Indianapolis and Pittsburgh, record September totals in parts of the Chicago area, and lighter rain in New York and Washington, D.C.; many southern and western sites such as Los Angeles, Houston, and Denver recorded zero. These patterns align with a frontal system bringing cooler, moist air from Iowa eastward while high pressure kept the Rockies and Southwest dry. Official NWS daily summaries provide the authoritative resolution data, with no further model updates expected.