Recent forecast guidance from multiple models shows a cooler air mass and possible patchy rain influencing São Paulo overnight into September 2, with projected minimums clustered around 11–13 °C. This aligns with the closely matched market-implied probabilities near 50% for those exact thresholds and slightly lower odds for values outside the 10–14 °C range. September climatology places typical overnight lows near 12 °C, while current steering patterns and surface pressure gradients introduce modest uncertainty in the precise timing and extent of radiational cooling or cloud cover that could shift the recorded minimum by 1–2 °C. Updated model runs and official observations over the next 24–48 hours will likely refine these outcomes.