Current trader sentiment for Seoul's highest temperature on March 28 clusters tightly around 14-18°C, driven by ensemble forecasts from the Korea Meteorological Administration (KMA), ECMWF, and GFS models projecting mild highs of 15-17°C under a developing high-pressure ridge over the Korean Peninsula. This setup favors southerly winds advecting warmer air from the south, potentially pushing readings to 18°C or higher in 19% of scenarios, while residual cold air outbreaks from Siberia—evident in recent model divergences—cap outcomes at 14°C or below with comparable odds. Historical March 28 averages sit at 12-13°C (1981-2010 baseline), but urban heat island effects in central Seoul add 1-2°C locally, amplifying upside risk; KMA's evening update could refine these probabilities amid low ensemble spread.