Recent Korea Meteorological Administration guidance points to a maximum of 29°C in the Seoul-Incheon area on August 21, with morning cloud cover giving way to scattered showers by afternoon. This outlook has tempered trader expectations after several preceding days reached 32–33°C under clearer skies. Key differentiating factors include the extent of daytime insolation reduction from increased cloud fraction and precipitation probability (30–60% range), modest onshore flow that can moderate peak heating, and the precise timing of any convective cells. Ensemble spread in short-range models creates the tight clustering around 27–29°C, as even modest shifts in rainfall onset or coverage could push the daily high one degree either way. Updated KMA model runs and afternoon observations over the next 48 hours will be the primary near-term catalysts for further market movement.