**Persistent rain, heavy cloud cover, and high humidity on August 22 are suppressing peak daytime heating in the Seoul-Incheon area, keeping forecast highs tightly clustered around 27–31°C across major models.** Official guidance from the Korea Meteorological Administration (KMA) points to a daytime maximum near 30°C under mostly cloudy skies with scattered showers or thunderstorms, while global models such as those referenced by the Met Office and aerodrome TAFs range from 27–31°C depending on the exact timing and intensity of precipitation. Widespread cloudiness and moisture from an ongoing weather system limit solar insolation, preventing the stronger warming that would push readings toward 32°C or higher; historical climatology for late August shows typical highs near 29–30°C, but the current rain pattern favors values at or slightly below that baseline. Model consensus remains modest on the precise peak because small differences in shower timing or brief clear spells can shift the daily maximum by 1–2°C, which explains the closely matched market-implied probabilities around 28°C (23.5%) and 29°C (30.5%). Updated short-range guidance and observational trends over the next 24–48 hours will be the key drivers for any further refinement in trader positioning.