Official meteorological observations recorded a daily maximum of 24°C in Mexico City on September 9, aligning with the market's near-certain outcome. This value reflects typical late-summer conditions at the city's high elevation, where persistent cloud cover, scattered showers, and moderate humidity suppressed peak heating despite seasonal solar input. Forecasts from multiple models converged on highs near 22–25°C, with actual readings settling at the precise threshold traders anticipated. The consensus draws from real-time station data rather than projections, though minor revisions in post-processing or station-specific measurements could theoretically alter resolution if thresholds are narrowly defined.