**Trader consensus on a 28°C daily maximum in Seoul for June 15 aligns with official observations from the Korea Meteorological Administration (KMA), which reported a peak temperature of exactly 28°C under mostly clear to intermittent cloud conditions.** Early June climatology in Seoul typically features daytime highs of 26–30°C as the East Asian summer monsoon begins to influence the region, with moderate humidity, light southerly winds, and limited daytime heating from partial cloud cover keeping temperatures from exceeding the mid-20s Celsius. Recent short-range model guidance from KMA and international ensembles converged on this value after incorporating surface observations and steering patterns that suppressed stronger warm advection. The market-implied near-certainty reflects verified station data rather than forecast uncertainty, as resolution depends on KMA’s official daily high recorded between 9 AM and late afternoon. A realistic challenge would require a post-analysis revision to the station reading or an unrecognized microclimate effect at the primary reporting site, though both are rare once preliminary observations are confirmed.