Traders see the 21–23°C band as most probable for São Paulo’s July 7 daily maximum because ensemble forecasts from INMET and global models show a stable winter pattern with light winds, clear skies, and dry subtropical air yielding afternoon peaks near the climatological 22°C average. Recent model runs indicate minimal frontal influence or moisture advection that could suppress or boost readings, keeping outcomes tightly clustered while the urban heat island effect adds minor variability. Official resolution relies on INMET surface observations at the city’s primary station, and any last-minute shift in steering flow or boundary-layer mixing could tip the exact high within this narrow range before the market closes.