**Trader consensus clusters tightly around 25–27°C for São Paulo’s August 7 maximum, with 26°C leading at 24.5% implied probability, followed closely by 25°C (23.0%) and 27°C (20.5%).** This narrow spread reflects model uncertainty over the timing and strength of an approaching cold front. A high-pressure system has maintained stable, above-average conditions across the Southeast earlier in the week, but INMET and regional guidance now highlight increasing cloud cover and scattered showers (locally up to 16 mm) expected Friday as the front reaches southern and eastern São Paulo. These factors limit daytime heating through reduced insolation and enhanced boundary-layer mixing. Climatological August averages near 23–25°C provide a baseline, while recent above-average anomalies have been tempered by the frontal passage. Global and regional model ensembles show the greatest divergence on exact front arrival and precipitation timing, producing the observed market clustering and sharply lower probabilities above 28°C. Updated INMET bulletins and afternoon model runs through resolution will be the key near-term catalysts.