**Persistent below-normal rainfall throughout August has positioned totals well under historical averages, driving trader consensus toward the <150 mm bin at 72% implied probability.** Korea Meteorological Administration observations show Seoul accumulating just 166 mm by month-end—48% of the 348 mm climatological normal—with most days recording little to no precipitation until late-month events. A stationary front and associated heavy downpours on 30–31 August delivered localized additions of 20–60 mm in the Seoul metro area, insufficient to close the deficit. Warmer-than-average temperatures and limited monsoon influence suppressed convective activity earlier in the month, while model guidance and recent KMA updates confirm minimal further accumulation before resolution. This data trajectory, combined with the approaching end of the observation window, reinforces market-implied odds favoring the lowest outcome range over mid- or high-precipitation bins.