Recent forecasts from the Korea Meteorological Administration and international models indicate Seoul's overnight minimum on June 16 will likely settle near 18–20°C amid stable early-summer high pressure, light southerly winds, and partly cloudy skies that moderate radiative cooling. The tight clustering of market-implied odds between 19°C and 20°C reflects this narrow expected range, with small differences driven by precise timing of any thin cloud layers or urban heat-island retention that can raise the recorded low by 1°C. Historical June minima average around 17–19°C, so current guidance sits slightly above the long-term baseline while remaining sensitive to the next 48-hour model updates from KMA and NOAA ensembles before resolution.