Recent forecasts from models including timeanddate and regional guidance center São Paulo’s overnight low for August 26 near 15°C under overcast skies, light southeasterly flow, and residual moisture from an approaching cold front or low-pressure system. This produces the tight market clustering around 14–16°C, as modest differences in predicted cloud thickness, boundary-layer mixing, and timing of any showers alter radiative cooling by 1–2°C. August climatology shows typical minima of 13–14°C, so traders assign low probability to readings below 12°C or above 18°C absent a stronger front or clearer skies. Updated model runs and official INMET or CPTEC guidance over the next 24 hours remain the key variables that could shift the narrow spread between the leading contracts.