Recent forecasts from the Korea Meteorological Administration and supporting models show Seoul and Incheon under persistent cloud cover with scattered showers and thunderstorms expected through the afternoon of August 21, limiting solar heating and capping the daily maximum near 27°C. This aligns with observed conditions featuring overnight lows around 25°C and daytime peaks suppressed by high humidity, light winds, and precipitation probabilities exceeding 50% in the peak heating window. Traders assign overwhelming probability to exactly 27°C because current observational trends and ensemble guidance show little room for significant deviation without a rapid clearing of skies. A faster-than-expected end to rain or stronger afternoon insolation could still push readings to 28°C or higher, while heavier or more prolonged precipitation would more likely hold the high at or below the consensus level.