**Trader sentiment for Seoul’s June 13 high temperature centers on the narrow spread among 26–28 °C outcomes because official guidance from the Korea Meteorological Administration and global models still shows modest day-to-day variability in cloud cover, humidity, and low-level wind flow two days out.** Early June climatology places Seoul’s average daily maximum near 27–29 °C under transitional pre-monsoon conditions, with sea-breeze moderation and occasional upper-level troughs capable of trimming highs by 1–2 °C or allowing brief clearing that adds the same amount. Current model consensus points to mostly cloudy skies with light southerly flow and dew points in the upper teens Celsius, conditions that typically cap afternoon temperatures in the mid-to-upper 20s rather than permitting full June sunshine-driven peaks near 30 °C. The closely matched 27 °C (33.5 %), 28 °C, and 26 °C probabilities reflect traders weighting the remaining uncertainty in boundary-layer moisture and any weak frontal passage against the strong historical baseline for early-June maxima. Updated short-range guidance and any shift in the subtropical ridge position over the next 24–48 hours will be the key data releases that can tilt the market.