The market's near-certain positioning on a 0°C minimum reflects official observations from Buenos Aires meteorological stations confirming that exact low on September 6. In early Southern Hemisphere spring, regional temperatures often hover near freezing under clear, calm conditions that promote radiational cooling overnight, consistent with historical September baselines around 1–4°C. Authoritative records from the national weather service provide the resolution data, with model consensus and real-time measurements aligning closely on this threshold. Minor discrepancies in station siting or rounding protocols remain theoretically possible but lack supporting evidence here, leaving the outcome firmly anchored by verified readings.