Due to the influence of a low-pressure system and southwest airflow, a heavy rain advisory was issued for the Yunlin, Chiayi, and Tainan regions on July 28, 2025. Chiayi County urgently announced work and school suspensions in the morning. TSMC’s Chiayi AP7 advanced packaging plant reportedly experienced flooding, with some areas submerged up to knee level. On-site workers were wading through muddy water, and construction operations were affected.