**Trader sentiment for Seoul's August 2026 total precipitation remains tightly balanced across bins from under 150 mm to 500 mm+, reflecting substantial uncertainty about rainfall accumulation over the final three weeks of the month.** Historical climatology shows August averages near 250–350 mm as the East Asian summer monsoon wanes after its July peak, with precipitation shifting toward shorter, more intense convective bursts and occasional typhoon influences rather than prolonged frontal rain. Current conditions feature ongoing heatwave patterns that can suppress widespread rain while increasing atmospheric moisture available for localized downpours. A developing tropical depression (KMA No. 27) and potential subsequent typhoon tracks represent the dominant near-term variable: systems steering moisture toward the Korean Peninsula could deliver 100–300+ mm in a few days, elevating totals into the 400–500 mm or higher range, whereas a more easterly or weakening track would favor drier conditions and push outcomes toward the lowest bins. Model consensus on steering patterns and sea-surface temperature influences remains divergent, with traders weighting both the declining seasonal baseline and the binary potential for one or two high-impact events. Official updates from the Korea Meteorological Administration on typhoon evolution and extended-range precipitation outlooks are the key near-term catalysts likely to shift implied probabilities.