**Recent forecast updates from the Korea Meteorological Administration and ensemble models position 33–34°C as the most probable range for Busan’s August 23 maximum, driven by the strengthening North Pacific high and gradual clearing after earlier cloud cover and showers.** Humid subtropical air under this ridge supports daytime heating, with southerly or southeasterly flow limiting stronger ventilation while dew points near 24–26°C maintain elevated heat indices. Current 10-day guidance shows highs climbing from ~29–31°C on August 21–22 to 31–34°C on the 23rd as skies clear, consistent with historical late-August climatology where Busan averages near 30–32°C but can spike higher under persistent high pressure. Traders assign the highest implied probability (42%) to 34°C because recent model runs and official outlooks emphasize the upper end of the 30–34°C envelope if afternoon insolation peaks without significant marine-layer influence. Lower probabilities for 35°C+ or sub-32°C reflect the narrow uncertainty band in short-range guidance ahead of the event.