Associate Professor Dr. Seri updates on the rainfall situation, reassuring residents of Bangkok and the metropolitan area that rain is expected to lessen progressively and no additional rain will fall tonight. He also explains why this year’s flooding is not a "mega flood" like in 2011 (B.E. 2554). The term "mega flood" refers to the massive flood event in 2011.
On 26 September 2026, Associate Professor Dr. Seri Supharat, Director of the Climate Change and Disaster Center at Rangsit University and Vice President of the National Disaster Warning Council Foundation, posted a message assuring residents of Bangkok and the surrounding metropolitan area to rest easy, as no additional rain is expected tonight. He also explained why this year’s flooding is not considered a mega flood like in 2011.
He stated: Why debate the term "mega flood"? The Climate and Disaster Center at Rangsit University and the National Disaster Warning Council Foundation updated the risk assessment for heavy to very heavy rainfall and evaluated the severity of the 2026 flood situation as of the evening of 26 September, finding that...
The latest hourly rainfall forecast for tonight through early tomorrow morning (26-27 September) shows a decreasing trend. Residents of Bangkok and the metropolitan area can rest assured that no additional rainfall will add to the flooding. However, the difficulties in daily life and travel remain, depending on local conditions, which require urgent recovery efforts to return to normal.
Nevertheless, the movement of a strong low-pressure area toward the west will strengthen the southwest monsoon winds. Therefore, provinces in the western region still face the risk of heavy rainfall on 27 September. Monitoring tomorrow’s forecast remains essential.
The debate over the term "mega flood" can be clarified by the accumulated floodwater volume passing through Nakhon Sawan Province (see attached image). At the same time, the floodwater volume in 2026 is about 4.3 billion cubic meters, whereas in 2011 it was 15 billion cubic meters—roughly three times larger—making it a completely different scale.
However, the flooding in central Thailand and Bangkok this time has affected nearly all areas, leading to the declaration of disaster zones covering all 50 districts. Shortages of goods in convenience stores and widespread public concern reaching panic levels mean this is not an ordinary event. Some may still refer to it as a "mega flood," depending on their definition.
Information courtesy of the Facebook page of Associate Professor Dr. Seri Supharat.