**Persistent cloud cover and widespread heavy rain from an active late-summer weather system are suppressing daytime heating in the Seoul-Incheon area, keeping the highest temperature on track for 25–26 °C on August 31.** Official and ensemble forecasts from sources including the Korea Meteorological Administration, European models, and U.S. guidance show an overcast day with near-continuous showers or thunderstorms, high humidity (90 %+), and easterly to northeasterly flow. These conditions limit solar insolation and produce a narrow diurnal range, with most guidance converging on a maximum of 24–26 °C (roughly 75–79 °F). The latest model runs as of August 30 have shown little change in this outlook, reinforcing the market’s heavy weighting toward 25 °C (71 % implied probability) and 26 °C (24 %). Historical late-August climatology for Incheon features average highs near 28–29 °C, so the current pattern represents a notable cool anomaly driven by the persistent moisture and cloud deck. Resolution hinges on the precise peak reading at the official Incheon station; any unexpected clearing could allow a brief spike toward 27 °C, but the overwhelming consensus favors the lower end of the distribution.