Official meteorological stations in Sao Paulo recorded a daily maximum temperature of 24°C on June 9, establishing the outcome that now carries a 100% market-implied probability. This reading reflects standard winter conditions in the Southern Hemisphere, where subtropical high pressure and reduced solar insolation typically limit highs to the low-to-mid 20s Celsius. No anomalous warm-air advection or urban heat-island effects pushed readings higher, and model consensus from regional forecasts aligned closely with the eventual observation. While final quality-controlled data from Brazil’s national weather service could theoretically be revised, historical precedent shows such adjustments rarely exceed 1°C for urban stations.