**Trader sentiment for the highest temperature in Seoul (Incheon) on August 29, 2026, reflects tight clustering around 29–30°C (combined ~74.5% implied probability), driven by late-summer atmospheric conditions and short-range forecast uncertainty.** Official guidance from the Korea Meteorological Administration and Incheon International Airport forecasts a daytime maximum near 30°C under partly to mostly cloudy skies with a 50–70% chance of showers or thunderstorms. Ensemble and global models show modest spread due to variable cloud cover, timing of any convection, and weak westerly flow that can enhance or suppress peak heating. Incheon’s coastal location adds a moderating sea-breeze influence that often caps temperatures relative to inland Seoul. Key differentiating factors include solar insolation under broken cloud decks versus clearer intervals, boundary-layer moisture and any evaporative cooling from scattered rain, and the precise evolution of a weak upper-level trough. Historical late-August climatology for the region centers near 29–30°C, so the market is pricing the narrow range of outcomes consistent with current model consensus and typical day-to-day variability in this regime. Newer model runs or afternoon updates on cloud trends and precipitation timing remain the primary near-term catalysts.