Traders see comparable odds for extreme high or low August precipitation in Seoul because the post-monsoon period features high natural variability driven by typhoon tracks and localized convective activity rather than steady frontal rains. After the Changma rainy season typically ends in late July, totals depend on the frequency and intensity of tropical cyclones steered by the subtropical high, plus soil moisture feedbacks and upper-level dynamics that models struggle to resolve a month ahead. Historical averages near 288 mm mask large year-to-year swings from under 150 mm in suppressed years to well over 500 mm when multiple systems make landfall, leaving the 500 mm+ and sub-150 mm brackets nearly tied at market-implied levels near 45 % and 41 %. Updated Korea Meteorological Administration outlooks and ensemble forecasts expected in early August will likely shift sentiment as steering patterns clarify.