Official observations from Argentina’s National Meteorological Service recorded a minimum temperature of 5°C or lower in Buenos Aires on September 9, 2026, driven by a lingering polar air mass and clear nighttime radiative cooling under light winds. This aligns with the sharp cooldown earlier in the month, when minima dipped to 2.4°C on September 6, and placed the day well below the September climatological average low near 10–11°C. Trader consensus at 100% for 5°C or below reflects verified station data rather than forecasts, though minor adjustments could arise from final quality-controlled readings or station-specific variations within the metropolitan area. No further model updates or observational revisions are expected to alter resolution.