Recent INMET and global ensemble forecasts indicate a cooler southeasterly flow and increased cloud cover will limit daytime heating in São Paulo on August 22, keeping the maximum temperature centered near 21–23 °C. Subtle differences among model solutions—primarily the timing and coverage of any late-day showers and the strength of low-level mixing—create the tight clustering of trader-implied probabilities across 21–24 °C outcomes. Historical August climatology places the long-term average high near 23 °C, so the current setup reflects a modest negative anomaly driven by transient synoptic patterns rather than seasonal norms. Updated model runs expected overnight will likely refine the exact peak and determine whether the market narrows toward the lower or upper end of that range.