Recent GFS model runs and ensemble guidance indicate overnight lows near 19°C for São Paulo on October 10, driven by moderate easterly flow, scattered cloud cover, and limited radiative cooling amid scattered thunderstorms. This places the 19°C outcome at the center of trader consensus, with 17°C or below reflecting scenarios of clearer skies or stronger nocturnal cooling that would enhance surface heat loss. Higher thresholds around 20–22°C align with greater cloud persistence or warmer advection, while the tight clustering of probabilities underscores model spread in boundary-layer moisture and timing of convective activity. Updated runs from official agencies will refine these distinctions ahead of the 24-hour minimum observation.