Forecast models from sources including GFS and regional agencies indicate São Paulo's minimum temperature on September 29 will likely fall in the 19–22°C range, driven by stable high-pressure influence, light variable winds, and overnight cloud cover limiting radiative cooling. Historical September baselines show typical minima near 12–14°C, but recent warm anomalies and a passing front have elevated readings, with daytime highs projected above 30°C. The near-even market split between ≤15°C and ≥25°C outcomes reflects model spread on exact overnight conditions—particularly how much moisture and wind shear may moderate the low—while single-degree buckets cluster around expected values. New runs and local monitoring agency updates over the next 48 hours will clarify resolution thresholds.