Recent ensemble forecasts from the Korea Meteorological Administration point to a mild spring night in Seoul on May 20, with minimum temperatures most likely settling between 15 °C and 18 °C. Model consensus highlights modest radiative cooling under partly cloudy skies and light southwesterly flow, limiting overnight drops compared with historical mid-May averages near 12 °C. Key variables differentiating the tightly bunched leading outcomes include the precise timing of any frontal passage and the depth of boundary-layer mixing, both of which can shift the recorded low by 1–2 °C. Updated model runs and official guidance released over the next 48–72 hours will refine these probabilities ahead of resolution.