Trader consensus favors 175-200 mm total precipitation in Seoul for September, aligning closely with historical averages of 143-184 mm as the East Asian monsoon wanes and wet-day probabilities decline sharply from ~39% early in the month. Primary drivers include lingering stationary fronts, occasional typhoon influences, and warm Yellow Sea sea-surface temperatures that can intensify late-summer systems, though long-range outlooks point to cooler-than-average temperatures and a slight tilt toward near-normal or drier conditions under strengthening El Niño. Recent heavy late-August rains across central Korea highlight ongoing moisture transport but do not directly alter September totals. Key resolution thresholds hinge on official Korea Meteorological Administration accumulations, with model runs through early September providing the next major updates.