Recent forecasts from Argentina’s Servicio Meteorológico Nacional and global ensembles such as GFS and ECMWF indicate a maximum of 17–19 °C for Buenos Aires on May 18 under stable post-frontal conditions, with moderate southerly winds limiting daytime heating below the month’s 19 °C climatological average. This places the market’s leading 16 °C outcome in a zone of genuine model uncertainty driven by variable afternoon cloud cover and possible urban heat-island effects at the Aeroparque or Ezeiza stations used for official resolution. The tight clustering of implied probabilities across 15–18 °C reflects traders’ assessment that small shifts in wind direction or insolation could easily alter the observed peak by 1–2 °C before the day’s final reading.