Recent forecasts from multiple models indicate a high near 12–13°C in Buenos Aires on September 5, driven by post-frontal southwesterly flow advecting cooler maritime air after a cold front passage earlier in the week. Strong SW winds of 15–25 km/h will enhance mixing and limit daytime warming, while mostly clear to partly cloudy skies permit moderate solar insolation but fall short of typical early-spring values around 18°C. Ensemble guidance shows tight clustering in the 11–14°C range, with small differences in maximum temperature hinging on exact wind speeds, boundary-layer mixing depth, and any lingering low-level moisture that could suppress the peak. Market-implied odds favor the 12–14°C outcomes because these align with the latest deterministic and ensemble runs from sources including GFS, ECMWF analogs, and local observations, while higher or lower extremes would require unexpected shifts in steering flow or cloud cover. Updated model runs and official Servicio Meteorológico Nacional guidance over the next 48 hours will refine the precise peak.