**Trader consensus for Busan's June 30 maximum clusters around 27–28°C (58% combined implied probability), reflecting model guidance near or slightly above late-June climatological norms of roughly 26–27°C.** Coastal marine influences from the Korea Strait, including sea breezes and elevated humidity ahead of the East Asian monsoon, are expected to moderate daytime heating and cap extremes. Recent KMA short-range forecasts and ensemble runs highlight potential for isolated showers or increased cloud cover that further limits insolation, while any clearer intervals could allow modest warming toward 29°C. With resolution imminent, traders are weighting the narrow range of official guidance and noting that updated model output or observed trends over the next 48 hours could shift probabilities among the tightly grouped central outcomes.