**Trader consensus centers on 26°C as the most likely high for Seoul/Incheon on September 14, reflecting model agreement on moderate autumnal cooling under northwest flow.** Multiple forecasts, including GFS-based guidance and local sources, project a daytime peak near 26–27°C (79–80°F) with partly cloudy skies, light to moderate northwest winds, and negligible precipitation risk. Overnight lows around 18–20°C support a modest diurnal range consistent with post-monsoon conditions. Current surface observations from the Korea Meteorological Administration show temperatures in the low-to-mid 20s°C with a shift to westerly and northwesterly winds, reinforcing the cooling trend as a high-pressure ridge builds. This aligns with historical September norms for the region, where highs typically decline from summer peaks but remain above 25°C before stronger cold-air intrusions later in the month. Model consensus shows limited spread, with no strong signals for either significant warming or rapid cooling that would push outcomes toward 28°C+ or 24°C or below. The market’s heavy weighting toward 26°C (over 50% implied probability) captures this stable forecast picture, with secondary support at 25°C reflecting minor downside uncertainty in timing of peak heating.