Recent model runs from INMET and GFS indicate overnight lows in São Paulo on October 9 will likely settle between 18–22 °C under a persistent warm, moist air mass advecting from the northwest, with only isolated showers expected to limit radiational cooling. This setup favors the market’s leading outcomes near 19 °C or 25 °C+, as dew-point depressions remain modest and cloud cover moderates temperature drops after sunset. Ensemble spread remains notable because steering flow and convective timing can shift minimums by 2–3 °C, keeping the 15 °C-or-below and warmer bins closely matched. Updated model guidance and official INMET briefings ahead of the overnight period will be the key catalysts for any further odds movement.