Traders see roughly equal odds (34.5%) for a 2–5 °C minimum in Buenos Aires on August 21 because official forecasts and ensemble models cluster tightly around 4–6 °C, reflecting modest uncertainty in the precise overnight low. Clear skies and light winds are enabling strong radiative cooling after a daytime high near 12–14 °C, while the urban heat island and proximity to the Río de la Plata moderate extremes. Historical August minima average near 9 °C, so this cooler pattern stems from a transient high-pressure system suppressing cloud cover. Resolution hinges on the Servicio Meteorológico Nacional’s official station reading, with any late-model shift or wind change able to nudge the outcome across the closely matched thresholds.