Recent numerical weather prediction runs, including GFS and ECMWF guidance, point to a maximum temperature near 27–28°C in Busan on September 28 under mostly cloudy skies, light northwest winds, and low precipitation chances, establishing the narrow spread between the leading market outcomes. These conditions align with late-September climatology for the region, where typical highs average 24–25°C but have trended slightly warmer amid persistent warm advection. Model consensus on afternoon peak timing and modest cloud cover reduces the likelihood of outliers above 29°C or below 26°C, while minor differences in boundary-layer mixing and sea-breeze effects explain the tight clustering around 27–28°C. Korea Meteorological Administration observations tomorrow will resolve the market, with any late forecast adjustments potentially shifting probabilities in the final hours.