Recent model runs from sources like GFS and regional forecasts indicate a daytime high near 30–32 °C for São Paulo on September 30, consistent with the tight clustering of trader-implied probabilities around those outcomes. Above-average spring temperatures across the Southeast, driven by northwesterly flow and limited cloud cover early in the day, support the upper end of that range, while scattered thunderstorms and increasing humidity later could cap the peak or shift it lower. Historical September maxima average near 25–26 °C, making the current warmth notable. Traders appear to weigh the balance between model consensus and precipitation timing, with fresh official guidance from INMET and overnight model updates likely to refine resolution odds before the day concludes.