Official forecasts from Brazil’s National Institute of Meteorology (INMET) and supporting international models consistently projected a daily maximum near 23 °C for São Paulo on June 6 under typical early austral winter conditions, including broken cloud cover and light southeasterly flow that limited daytime heating. This aligns with the city’s June climatological average high of approximately 22–23 °C and recent observational trends showing moderation from earlier-month warmth. Post-event station data have now confirmed the peak reached exactly this threshold, producing the market’s overwhelming 100 % implied probability on the 23 °C outcome. Minor model spread or station-to-station differences could theoretically shift the recorded maximum by 1 °C, though current evidence makes such revisions unlikely before final resolution.