Official forecasts from the Korea Meteorological Administration project a morning low of 17°C for both Seoul and Incheon on September 30, driven by clear to partly cloudy conditions overnight with northwest winds and no significant cold advection. Multiple regional models align on this overnight minimum near 17–18°C before daytime warming to 25–26°C, consistent with late-September climatology for the region. The 100% market-implied probability reflects this tight model consensus and real-time observations showing temperatures stabilizing around that threshold. A sudden unforecasted frontal passage or localized measurement variance at official stations could theoretically alter the recorded low, though current atmospheric patterns make such shifts highly improbable before resolution.