Recent Korea Meteorological Administration forecasts and ensemble model runs indicate Busan’s daily maximum temperature on May 17 will reach exactly 30 °C, driven by southerly advection of warmer air masses across the Korean Peninsula under a stable high-pressure regime. Coastal sea-breeze circulation, typical for Busan’s location, is expected to moderate peak readings precisely at this threshold rather than allowing further inland-style warming. Historical May climatology for the region shows average highs climbing through the mid-20s °C with occasional 30 °C spikes under similar synoptic patterns, lending additional support to the market’s near-certain pricing of the 30 °C outcome. Resolution hinges on the official Gimhae International Airport station reading, and only a notable increase in cloud cover or an earlier-than-forecast sea breeze could realistically shift the peak into the adjacent 29 °C or 31 °C range.