Recent Korean Meteorological Administration forecasts indicate a cloudy Friday, August 21, with afternoon showers (60% probability) and a maximum of 29°C for Seoul/Incheon, moderating peak heating compared to recent sunnier days near 32°C. This cloud cover and precipitation risk create the tight clustering of trader-implied odds around 28–29°C, as reduced solar insolation and evaporative cooling limit afternoon warming. Ensemble models show modest uncertainty in rain timing and intensity, which could shift the daily high by 1–2°C depending on whether showers arrive before or after peak heating. Historical August baselines for the region average highs near 29°C, providing context for why probabilities spread across 27–30°C rather than converging on a single outcome. Updated model runs and official briefings in the next 24–48 hours will refine these variables ahead of market resolution.