Recent observational data and Korea Meteorological Administration analyses confirm unseasonably warm conditions across the Seoul-Incheon region on October 12, driven by southerly flow from a southern low-pressure system combined with easterly winds around a high-pressure ridge. These patterns produced daytime maxima aligning with the 28°C threshold at official stations, consistent with historical analogs for late-season heat events and exceeding typical mid-October baselines of 20–23°C. Model consensus and real-time measurements reinforced this outcome ahead of evening rain onset, which began cooling temperatures. A shift in steering patterns or heavier localized precipitation could have capped readings below this level, though current synoptic conditions and verified observations make such revisions unlikely.