Forecast models from the Korea Meteorological Administration and regional ensembles indicate a highest temperature in Busan on June 13 most likely in the 27–29°C range, with 28°C holding the highest implied probability at 34.5%. This narrow clustering reflects typical early-June conditions: moderate onshore flow from the East Sea limiting daytime heating, combined with variable cloud cover and humidity that can shift afternoon maxima by 1–2°C. Recent short-range guidance shows mostly stable high-pressure influence with low precipitation chances, though small differences in predicted insolation or boundary-layer mixing explain the tight spread among 27°C (21%), 28°C (34.5%), and 29°C (25.5%). Historical June averages near 26°C provide baseline context, while model uncertainty on exact cloud timing keeps probabilities distributed rather than concentrated on a single outcome. Updated KMA runs and satellite observations over the next 48 hours will refine these thresholds ahead of market resolution.