**Official observations from the National Weather Service placed Seattle’s maximum temperature on September 28, 2026, at 65 °F, aligning precisely with the 64–65 °F bin.** This outcome reflected a typical late-September pattern under mostly overcast skies with light southerly flow, yielding daytime highs near the climatological average of roughly 66 °F for the date. Model guidance issued in the preceding days consistently projected a narrow range around this value, and post-event verification from Seattle-Tacoma International Airport and downtown stations confirmed the reading without upward revision. With the event concluded and data finalized, market-implied odds reached 100 % on that interval. Only an unlikely reanalysis of official records or use of an atypical station could alter the result at this stage.