The market's 100% consensus on a 64-65°F high for Seattle on September 27, 2026, stems directly from post-event official observations confirming that exact range as the daily maximum, most likely at Seattle-Tacoma International Airport. Preceding forecasts from NOAA and local models anticipated mid-to-upper 60s under mostly sunny conditions with light northerly winds, aligning closely with climatological averages near 66-67°F for late September. With the date concluded, real-time station data and preliminary climatological summaries eliminated remaining forecast uncertainty. Only an improbable official data revision or station-specific anomaly could shift the outcome now.