Recent forecasts from Brazilian meteorological services indicate a cold front advancing across São Paulo state, introducing cooler maritime air and increased cloud cover that limits daytime solar heating on June 16. This setup favors maximum temperatures near 18–20°C, aligning with the market’s tight clustering around those outcomes, as models show modest variability in frontal timing and precipitation intensity that could shift the daily peak by 1–2°C. Historical June climatology places typical highs near 22°C, but the current synoptic pattern—marked by post-frontal stabilization and possible light rain—explains the downward pressure on extremes above 21°C. Updated INMET guidance and regional model runs over the next 24 hours will likely refine these probabilities as the front’s exact position becomes clearer.