In Chon Buri, Pattaya City took the brunt of the damage, its much-maligned drainage system completely overrun by hours of rain.
Citywide flooding can reach 30 centimetres deep after just 45 minutes during normal storms. Wednesday's deluge comtinued all day and night, leaving most parts of Bang Lamung District under a metre or more of water.
The Disaster Prevention and Mitigation Department director-general Chatchai Promlert flooding still persisted in parts of Chon Buri Thursday morning, with local officials scrambling to pump out the runoff while residents began digging out.