Clear skies and a stable high-pressure system over central Argentina have promoted strong radiational cooling overnight in Buenos Aires, with light southerly winds of 10–15 km/h reducing atmospheric mixing and allowing surface temperatures to drop efficiently after sunset. Official guidance from the Servicio Meteorológico Nacional and supporting models from Yr and the Met Office converge on a minimum of roughly 3–5 °C in the pre-dawn hours of August 21, aligning with the market’s heaviest implied probabilities clustered at 2 °C (35 %), 3 °C (46 %), and 4 °C (59 %). Modest forecast spread arises from small uncertainties in dew-point values and any residual cloud cover, while tail-risk outcomes such as –1 °C or below (27 %) or 1 °C (24 %) reflect the low but non-zero chance of stronger cooling under a temporary wind lull; warmer thresholds above 5 °C carry negligible odds given the entrenched winter pattern. Real-time station data and the next model runs will further tighten the range before resolution.