Recent forecasts from multiple models indicate clear to mostly clear skies over Busan on September 20 under building high pressure following rain on the 18th, with northeasterly winds of 10–14 mph. These conditions promote radiative cooling overnight, supporting minimum temperatures near 18–20°C—typical for the season but sensitive to exact cloud cover, wind mixing, and marine air influence. Trader sentiment splits between the 15°C-or-below and 25°C-or-higher brackets because small shifts in model guidance on timing of clearing or local urban heat effects could push the official low across key thresholds, while mid-range outcomes like 19–21°C align with current consensus runs yet carry lower implied probabilities. Updated National Meteorological Administration guidance and evening model releases will likely refine the range before resolution.