Current forecasts from the Korea Meteorological Administration and global ensemble models indicate overnight minimum temperatures in Seoul on May 18 will likely settle near 14°C, driven by clear to partly cloudy skies that enhance radiative cooling under a stable high-pressure ridge. This aligns with the market’s leading outcome at 31.5% implied probability, as historical May climatology shows typical lows ranging 12–16°C during the second week. Key variables modulating the final reading include wind speed, which limits mixing if calm, surface humidity affecting dew-point depression, and any late-arriving moisture that could raise the floor by 1–2°C. Traders appear to price in moderate uncertainty around model spread, with 13°C and 15°C outcomes each holding meaningful shares, while probabilities drop sharply below 12°C or above 16°C absent unusual synoptic shifts before resolution.