Latest numerical weather prediction models from major centers show Sao Paulo under stable winter high pressure on July 9, supporting afternoon highs of 22–24 °C at official stations such as Guarulhos, consistent with the market’s tight 35.5 % clustering on 23 °C and 24 °C. Key differentiating factors include boundary-layer mixing depth, surface insolation under mostly clear skies, and any late-day thin stratiform cloud that could suppress the peak by 1 °C. With July climatology centering near 22 °C and no strong cold fronts expected, small revisions in model soundings or observed wind shifts will determine whether the maximum settles at the lower or upper end of the favored range. Updated runs ahead of the evening observation window remain the next market-moving inputs.