Traders have converged on 23°C as the highest temperature recorded in São Paulo on July 31, 2026, reflecting confirmation from official station observations following the date. July climatology in the region typically features daytime maxima near 21–23°C under stable winter conditions, with dry air masses and limited cloud cover supporting modest afternoon warming. The market-implied certainty aligns with verified measurements from primary monitoring networks, where 23°C falls squarely within expected ranges absent anomalous heat advection or urban heat island amplification. Revisions to the official daily maximum remain possible only through post-processing corrections by agencies such as INMET, though historical precedent shows such adjustments are rare and usually minor once preliminary data are released.