Trader consensus at 100% for a 14°C low on September 13 reflects official minimum temperature readings from Mexico City stations, including those operated by CONAGUA and the Servicio Meteorológico Nacional. These surface observations, consistent with regional model outputs and nearby airport data, showed no colder overnight readings amid typical late-summer humidity and light winds. Historical September averages near 12–15°C provide climatological context, while the absence of cold fronts or clear-sky radiational cooling kept temperatures from dipping further. A post-event data revision from a primary station or inclusion of an unrepresentative microclimate site could theoretically shift the recorded low, though such adjustments are rare once preliminary reports are validated.