Recent Korea Meteorological Administration short-range guidance points to a minimum near 26°C for Seoul-Incheon on August 15 under mostly cloudy skies, light winds, and scattered showers, yet the market’s 49.5% implied probability on 25°C reflects trader expectations of modestly stronger overnight radiative cooling or late forecast revisions. Persistent regional heat and humidity have elevated baseline temperatures, while variable cloud cover modulates heat-trapping effects that typically limit nighttime drops to 1–2°C below daytime peaks. Incheon’s coastal and urban setting adds microclimate influences from the heat island and marine layer. Updated KMA ensemble runs and hourly observations through the overnight period will refine the exact low, with resolution hinging on whether the temperature falls to or below the 25°C threshold before 9 a.m. local time.