Recent model consensus from Argentine meteorological services points to a daytime high near 16°C in Buenos Aires on May 18, shaped by a cool southerly air mass and variable cloud cover that limits afternoon heating. Partly cloudy conditions expected under a strengthening high-pressure ridge will moderate temperatures around the seasonal average of 17–18°C, while any earlier clearing or delayed frontal passage could push readings to 17–19°C or keep them near 15°C. Traders assign the tightest probabilities to 15–17°C outcomes because ensemble forecasts show only modest day-to-day variability this far into autumn, with resolution hinging on the precise hour of peak insolation measured at Ministro Pistarini Airport.