The Royal Irrigation Department of Thailand stated that the total rainfall in Hat Yai, Thailand, reached 630 millimeters from November 19 to 21, marking the most severe rainstorm in 300 years.
According to Thailand's The Nation, the Royal Irrigation Department pointed out that strong monsoons brought a record-breaking total rainfall of 630 millimeters in just three days, from the 19th to the 21st, surpassing the record set in 2010.
The intense monsoon caused massive flooding in 10 southern provinces of Thailand, with Hat Yai City experiencing the severest rainstorm in 300 years.
The Royal Irrigation Department’s Smart Water Operations Center (SWOC) explained that since November 19, 2025, severe flooding has continuously affected the south. This was due to the combined effects of a strong monsoon trough and a low-pressure system covering the southern and lower southern regions. This resulted in strong to extremely heavy rainfall in areas stretching south from Chumphon Province, causing severe floods in 10 provinces.
The 10 provinces include Chumphon, Surat Thani, Nakhon Si Thammarat, Satun, Songkhla, Phatthalung, Trang, Narathiwat, Pattani, and Yala. Many areas reported 24-hour rainfall amounts between 300 to 500 millimeters.
All districts in Songkhla Province experienced heavy rainfall, with Hat Yai recording a daily rainfall of 335 millimeters on November 21, 2025, the highest single-day record in 300 years.
From November 19 to 21, the total three-day rainfall reached 630 millimeters, surpassing the 428-millimeter record set during the Hat Yai floods in 2010. This also resulted in water depths ranging from 0.50 to 2.50 meters in urban areas of Hat Yai.