**Equal market-implied odds across temperature bins reflect substantial uncertainty in the exact daily maximum for Seoul/Incheon on August 31, driven by a forecast of widespread cloud cover, moderate northeast winds, and scattered showers or thunderstorms that will limit daytime heating.** Official guidance from the Korea Meteorological Administration and international models shows highs likely in the 24–28°C range, with peaks suppressed by reduced insolation and evaporative cooling from precipitation. Historical climatology places late-August maxima near 27–29°C under clearer skies, but the current synoptic pattern favors a cooler outcome near or below average. Traders are weighting model consensus and recent cooling trends from persistent cloudiness, while noting that clearer breaks or delayed rain could still push the peak toward the upper bins before resolution.