Official observations from Argentine meteorological stations recorded a minimum temperature at or below 2°C in Buenos Aires on September 14, 2026, driving the market's near-certain consensus on that outcome. Clear skies, light winds, and radiational cooling under a stable high-pressure system allowed surface temperatures to drop sharply overnight, consistent with early-spring climatology for the region when cold air masses advect northward. Model guidance and real-time station data aligned closely with this result, leaving little room for upward revision. Only an unprecedented post-event data correction or station-specific anomaly could alter resolution, an exceedingly low-probability scenario given multiple redundant measurement networks.