Official meteorological observations from São Paulo stations recorded a daily maximum of exactly 25°C on October 12, anchoring the market at 100% implied probability for that outcome. Persistent cloud cover, scattered thunderstorms, and elevated humidity—common during the transition into the wet season—limited daytime heating below the October average of roughly 31–32°C. Steering patterns and regional moisture influx further suppressed peak temperatures, aligning with National Meteorological Service data and model consensus. While data revisions or station-specific discrepancies remain theoretically possible, the convergence of multiple verified reports makes any shift in the final figure highly improbable.