**Trader sentiment for Busan's August 18 maximum temperature centers on 30–31°C as the most probable range, reflecting short-range forecast uncertainty two days out.** Multiple models and official guidance, including Korea Meteorological Administration runs, indicate daytime highs near or slightly above the seasonal average of ~30°C amid persistent influence from the North Pacific subtropical high, which favors warm, humid southerly flow. Coastal sea-breeze moderation, variable cloud cover, and scattered showers—some guidance shows 20–60% precipitation probability—introduce downside risk that could cap readings at 29–30°C, while clearer intervals or stronger subsidence could allow brief peaks near 32°C. Recent mid-August observations confirm above-normal temperatures with tropical-night conditions, yet no extreme heatwave or typhoon signals are evident. Resolution hinges on the official KMA observation at the primary Busan station, where small differences in afternoon insolation or timing of any convection will determine the exact maximum.