Official forecasts from the Korea Meteorological Administration and supporting model runs have converged on a daily maximum of 23°C for Incheon on September 12, driven by persistent cloud cover, light variable winds under 10 km/h, and stable high pressure limiting daytime heating. Real-time station observations through the afternoon have remained capped near this level, aligning with climatological September averages and producing the market’s near-certain 23°C outcome. Minor model spread on boundary-layer mixing or localized clearing could allow a brief excursion to 24°C, though current data and resolution criteria centered on official Incheon readings make such shifts unlikely before the daily close.