Current forecasts from the Korea Meteorological Administration point to a mild warming trend across the Korean Peninsula, driven by southerly airflow and limited cloud cover that could push Busan’s daytime high into the upper 20s Celsius on May 18. The tight contest between 29 °C and 30 °C in the market reflects genuine uncertainty in peak-temperature guidance, as small differences in boundary-layer mixing, sea-surface temperatures in the Korea Strait, and timing of any afternoon sea breeze can shift the maximum by a degree or two. Historical May climatology for Busan shows average highs near 23 °C, yet recent seasons have featured more frequent excursions above 28 °C amid broader regional warmth. Updated model runs and official briefings expected overnight will likely clarify whether conditions support a 29 °C or 30 °C resolution.