Recent forecasts from multiple models indicate a stable high-pressure regime over the Korean Peninsula, with mostly clear skies and light easterly winds expected through September 22. This setup favors modest overnight radiative cooling, producing minimum temperatures in the 18–21°C range at Incheon International Airport, consistent with the market's tight clustering around 18–20°C. Current runs show the overnight low likely settling near 19–20°C, slightly above the long-term September average of roughly 17°C, due to a lingering warm air mass. Key variables differentiating the leading outcomes include subtle differences in cloud cover timing and boundary-layer mixing; clearer conditions or lighter winds would favor the lower end near 18°C, while any increase in moisture or wind would support 20–21°C. Updated model guidance overnight and on the 21st will refine these probabilities ahead of the daily minimum.