**A hot, dry air mass has driven above-average temperatures across São Paulo on August 28, 2026, with official forecasts and model consensus centering the daily maximum near 31–32 °C under mostly sunny skies and low humidity.** This aligns with the market-implied odds, where 32 °C leads at 50 % and 31 °C follows at 27.5 %, as multiple sources (including CGE, IPMet, and international models) project highs of 30–33 °C with peak readings in the early-to-mid afternoon. Normal August maxima average around 22 °C, but the current synoptic pattern—characterized by northerly or northwesterly flow and subsidence—has produced a short-term heatwave, pushing readings well above the seasonal baseline without significant cloud cover or precipitation to moderate surface heating. Hourly guidance shows rapid warming from morning lows near 17 °C to afternoon peaks of 30–31 °C, with some runs briefly touching 33 °C or higher before cooling. Traders have priced in limited upside risk (33 °C at 12.5 %) because steering patterns and dry-air advection favor the 31–32 °C window, while the absence of recent model shifts or new observational data has kept probabilities stable ahead of final resolution.