Official Korea Meteorological Administration data place Seoul’s May 2026 total precipitation at approximately 123 mm, or 122 % of the long-term climatological normal near 100–110 mm, establishing the 120–130 mm band as the clear resolution. A low-pressure system that tracked across the peninsula on 20–21 May delivered the month’s heaviest rains, accounting for over 60 % of the seasonal total and pushing accumulations firmly into the observed range. Model consensus and real-time gauge networks showed limited divergence, reinforcing trader confidence. Only a late revision to the finalized KMA station figure or an unusually large discrepancy among Seoul’s reporting sites could shift the outcome, both of which remain low-probability events given the consistency of preliminary reports.