Official meteorological observations from stations in Mexico City confirmed a daily maximum of 22°C on September 7, 2026, under predominantly cloudy, rainy conditions that limited solar heating while aligning with seasonal norms for early September at the city's high elevation. Forecast models from sources including CONAGUA and international ensembles had projected highs near this value, with minimal spread once surface data arrived, reinforcing the market-implied odds through direct measurement rather than projection. Rare adjustments to preliminary readings or discrepancies across urban microclimates could theoretically alter the final figure, though such revisions remain uncommon once quality-controlled archives are published.