Trader consensus on a lowest temperature of 1°C or below in Buenos Aires on September 16 reflects confirmed observations from the National Meteorological Service showing rapid nighttime radiative cooling under clear skies after southerly cold air advection. Regional forecast models converged on this outcome, consistent with early-spring climatology where polar outbreaks produce sharp drops below typical September minima around 7–10°C. Official station data and multiple sensor readings reinforced the market-implied odds near resolution. Scenarios that could still challenge the outcome include minor revisions from urban heat-island buffering or precise hourly measurement windows near the threshold, though such adjustments appear improbable given the strength of the consensus data.