Thailand weather warning: heavy rain and flood risks through September 27

heavy rainfall flash floods monsoon trough water management weather warning

Thailand is facing a period of intense weather, with the Thai Meteorological Department issuing warnings for heavy to very heavy rainfall from September 23 to 27, 2026. A strong low-pressure area near the coast of Vietnam and an active monsoon trough are driving the conditions, posing significant risks of flash floods, forest run-off, and landslides, particularly in low-lying areas and near foothills.

In response to the weather, the Department of Disaster Prevention and Mitigation has coordinated with 70 provinces and Bangkok to monitor risks. The Royal Irrigation Department is managing water levels by adjusting the discharge from the Chao Phraya Dam to between 1,000 and 1,300 cubic meters per second, alerting 11 central provinces to potential rises in river levels.

In Bangkok, authorities are working on a long-term drainage project in collaboration with the Japan International Cooperation Agency (JICA). This initiative aims to upgrade the city's infrastructure to handle up to 100 millimeters of rainfall per hour to mitigate future flooding caused by climate change.

Entities

Andaman Sea · Bangkok · Bangkok Metropolitan Administration · Chao Phraya River · Department of Disaster Prevention and Mitigation · Gulf of Thailand · Japan International Cooperation Agency · Thai Meteorological Department · Thailand

Claims

What the coverage asserts, and how many sources carry each claim.

[● 5 SOURCES] The heavy rainfall increases the risk of flash floods, forest run-off, and landslides, particularly in low-lying areas and near foothills. www.naewna.com · www.innnews.co.th · www.chiangmainews.co.th · thestandard.co · thethaiger.com
[○ 1 SOURCE] Bangkok is developing a new drainage system designed to handle up to 100 millimeters of rainfall per hour in collaboration with JICA. www.wochenblitz.com
[● 5 SOURCES] Waves in the upper Gulf of Thailand are expected to reach 2 to 3 meters, exceeding 3 meters during thunderstorms. www.naewna.com · www.innnews.co.th · www.chiangmainews.co.th · thestandard.co · thethaiger.com
[DISPUTED] The Department of Disaster Prevention and Mitigation has coordinated with 70 provinces and Bangkok to monitor flood risks. www.chiangmainews.co.th
[○ 1 SOURCE] The Office of National Water Resources has issued warnings for flood-prone areas in the Eastern region. www.chiangmainews.co.th
[● 5 SOURCES] Heavy to very heavy rain is forecast across Thailand from September 23 to 27, 2026. www.naewna.com · www.innnews.co.th · www.chiangmainews.co.th · thestandard.co · thethaiger.com