Recent model runs and climatological data for subtropical São Paulo in late winter point to a daytime maximum near 21–23°C on August 22, keeping those bins clustered in the market. Persistent high pressure and limited moisture advection from the Atlantic have favored clear to partly cloudy skies with modest insolation, while a weak cold front passage or variable southeasterly flow could shave 1–2°C off the peak. Urban heat-island effects and precise boundary-layer mixing add further uncertainty to the exact maximum recorded at official stations, explaining why traders assign nearly equal weight to the three leading outcomes rather than a single temperature.