Recent ensemble forecasts from global models indicate a modest easterly flow over Buenos Aires on September 27, 2026, advecting cooler maritime air that caps daytime heating near 19–21 °C. Persistent cloud cover and a 40–60 % chance of light showers or drizzle further suppress maximum temperatures by limiting insolation, consistent with the tight clustering of market-implied probabilities around 19–21 °C. Historical September climatology shows average highs near 19–20 °C, so current guidance aligns closely with seasonal norms rather than anomalous warmth. Traders are monitoring the next ECMWF and GFS runs for refinements in boundary-layer moisture and wind speed, which will determine whether the peak reaches 22 °C or remains at 18 °C.