Official observations from Mexico City monitoring stations, including Benito Juárez International Airport, recorded a daily maximum of 25°C on September 13, 2026, consistent with the seasonal average high for the month in this high-elevation subtropical highland climate. Widespread cloud cover, light precipitation, and typical afternoon convective activity kept temperatures from exceeding this threshold, as confirmed across multiple model runs and real-time station data. Trader consensus at near-100% implied probability for 25°C reflects the convergence of verified measurements shortly after the observation window closed. Only significant post-event data revisions or discrepancies between official reporting agencies could alter the outcome.