**KMA forecasts set the overnight low for Seoul and Incheon on August 17 at 24°C under mostly cloudy to clear skies early, with showers developing mainly after midday and only 20% precipitation probability overnight.** Persistent summer humidity and scattered convective activity limit radiative cooling, keeping minimums near or slightly above seasonal averages of 22–23°C. Recent model runs show minor disagreements on exact cloud timing and shower onset that could shift the low by 1°C either way, supporting the tight market clustering around 23–25°C. Coastal Incheon measurements may run marginally cooler than central Seoul due to marine influence, while urban heat retention adds slight upward bias. Updated guidance ahead of the morning minimum window will likely refine probabilities.