**Trader consensus has converged on a 20°C high for Buenos Aires on September 9 because official meteorological observations confirmed that maximum temperature.** National Meteorological Service and local station data recorded a peak of 20°C under partly cloudy skies with northerly flow that allowed modest daytime warming from morning lows near 9–10°C. This aligns with typical early-spring conditions in the region, where September averages hover around 15–18°C and brief warm anomalies are common before frontal passages. With the date now past and verified readings in hand, alternative outcomes carry negligible probability. Only a substantial post-event data revision or redefinition of the measurement station could shift the outcome, scenarios that remain highly unlikely given standard reporting protocols.