**A cold front arriving Friday night into Saturday is the dominant driver, sharply cooling São Paulo from recent highs above 30°C and positioning the daily maximum near 21–23°C.** Official and model guidance from INMET, Met Office, Yr.no, and others converge on a Saturday peak of roughly 20–23°C under partly cloudy to mostly clear skies, light to moderate southeasterly winds, and dry conditions, with the warmest readings expected midday to mid-afternoon. This aligns directly with the market’s heaviest weighting on 22°C (37%), followed by 21°C (26%) and 23°C (23.5%). August climatology in São Paulo favors highs around 22°C, but the front’s advection of cooler maritime air, combined with rising surface pressure and reduced insolation from variable cloud cover, suppresses afternoon heating relative to the prior week’s heat. Minor spread across forecasts (18–23°C) reflects small differences in timing of clearing and wind strength, yet no major model divergence exists. With resolution only hours away, the latest observational trends and final model runs will determine whether the peak settles at the lower or upper end of the favored range.