**Trader sentiment for São Paulo’s June 29 maximum temperature centers on 25–26°C outcomes (combined ~67.5% implied probability) because short-range forecasts and ensemble guidance cluster in that narrow band under typical austral winter conditions.** São Paulo’s elevation near 760 m and its subtropical high-pressure ridge produce light winds, limited moisture, and variable cloud cover that caps daytime heating. Recent model runs show only modest differences in boundary-layer mixing and solar insolation, which can shift the daily peak by 1°C. Historical June climatology from INMET places average highs at 21–23°C, but recent observations (including a 25.7°C reading earlier in the month) indicate a mild pattern that supports the upper end of the seasonal range. No strong cold front or clear-sky surge is expected, keeping upside potential low and preventing 27°C+ from gaining traction. Minor forecast revisions on cloud timing or wind strength will likely decide whether the peak settles at 25°C or 26°C before official INMET verification.