Official forecasts from the Korea Meteorological Administration and supporting numerical weather models indicate a daytime maximum of 25°C for Incheon on September 30, with observed readings aligning closely through afternoon hours under partly cloudy skies and moderate southwesterly flow. This consensus across regional guidance and real-time station data underpins the market's near-certain positioning at exactly 25°C. Minor model spread in boundary-layer mixing or station-specific microclimates between Seoul and Incheon could produce small deviations, though current observations and post-frontal stabilization limit realistic upside or downside shifts before final recording.