**Recent official forecasts position the minimum temperature in Incheon (Seoul's primary observing station) near 24–25°C on August 21, 2026, aligning with the market's heavy weighting toward those outcomes.** Korea Meteorological Administration short-range guidance, updated as of August 18–19, explicitly projects a 25°C overnight low under mostly cloudy morning conditions transitioning to occasional afternoon rain. Complementary extended outlooks from AccuWeather and timeanddate.com cluster daily lows in the 24–25°C range (roughly 76°F), consistent with late-August climatology where typical Incheon minima fall between 22–26°C amid high humidity and frequent moisture. Scientific drivers include persistent warm, moist southerly flow typical of the East Asian summer monsoon tail, combined with limited nocturnal radiative cooling due to cloud cover and urban heat-island effects around the Incheon airport site. No strong cold-air advection or clear-sky radiational cooling is indicated in current model runs, keeping the distribution tightly centered on 24–25°C. Traders appear to be pricing in the consensus from official agency guidance rather than outlier scenarios, as probabilities for 23°C or below and 26°C or above remain low. Updated KMA and global model runs closer to the date will be the key data points likely to refine these implied probabilities.