Recent forecasts from agencies including the Korea Meteorological Administration and international models indicate clear to partly cloudy conditions over Incheon on September 23, supporting overnight radiative cooling to a likely minimum near 19–20 °C. Light easterly to southerly winds of 4–7 m/s and dew points around 17–19 °C limit mixing and evaporation, while modest humidity (70–85 %) and absent frontal systems reduce the chance of stronger cooling or warming. Key variables include any last-minute increase in low-level cloud cover, which could raise the minimum by 1–2 °C, versus clearer skies that might allow brief dips toward 18 °C. High-pressure dominance and seasonal transition from summer warmth keep extremes below 16 °C or above 24 °C improbable, aligning with the market’s dispersed probabilities around the central outcomes.