**Short-range forecasts from GFS and ECMWF models indicate a daytime maximum of 11–12°C in Buenos Aires on August 13, 2026, under a persistent high-pressure regime favoring clear to partly cloudy skies, strong overnight radiative cooling, and limited warm-air advection from the north.** This setup, typical of Southern Hemisphere winter, suppresses seasonal August averages near 17°C and produces cooler surface readings consistent with recent model runs. Light rain or overcast conditions noted in some guidance could further cap afternoon peaks by reducing insolation, while southeasterly winds around 14–20 km/h add modest mixing without significant warming. Historical climatology shows occasional cooler outliers in August when high pressure dominates, aligning with the tight market split between the 11°C and 12°C bins as traders weigh minor model spread and timing of any cloud or precipitation changes. New model updates or observational data ahead of the date remain the key variables that could shift implied probabilities.