Latest ensemble forecasts from the Korea Meteorological Administration and global models indicate peak temperatures in Busan on July 21 will likely reach 31–33°C under the influence of a strengthening subtropical high, with mostly sunny conditions favoring strong diurnal heating. Coastal sea breezes and residual monsoon moisture introduce key uncertainty, potentially capping the maximum below model consensus or allowing brief exceedances in urban areas. Traders assign the highest implied probability to 32°C because recent runs show modest upward revisions from prior days amid stable atmospheric patterns, while the tight spread between 32°C and 33°C reflects model spread on boundary-layer mixing and exact insolation. Updated guidance expected within 24 hours from KMA could further narrow outcomes ahead of market resolution.