Official Korea Meteorological Administration forecasts for August 17 point to a maximum near 30–32°C in the Seoul-Incheon region under mostly cloudy skies with a 60% chance of afternoon showers, creating the tight spread between 29°C and 30°C as the leading market-implied outcomes. Persistent cloud cover and precipitation reduce solar insolation and surface heating relative to clear conditions, while high humidity supports heat retention overnight and limits diurnal range. This aligns with climatological mid-August baselines of 29–31°C that trend lower amid elevated rain probabilities above 50%. Updated short-range model runs and KMA morning briefings will provide the next resolution-relevant data on exact timing and intensity of any showers.