The Department of Disaster Prevention and Mitigation (DDPM) has issued warnings for 39 provinces in northern, northeastern, and central Thailand to monitor for flash floods, flash floods, mudslides, and waterlogging. Meanwhile, three provinces in the south are advised to watch for strong waves and winds from 18 to 21 August 2026.
On 16 August 2026 at 19:20, Mr. Theerapat Kachamat, Director-General of the Department of Disaster Prevention and Mitigation (DDPM), announced that the Central Disaster Prevention and Mitigation Command Center has been monitoring weather conditions and risk factors. The Meteorological Department issued its second announcement (No. 156/2569) on 16 August 2026 at 05:00, warning of heavy to very heavy rain in upper Thailand between 18 and 21 August 2026. This is due to a monsoon trough crossing northern and upper northeastern Thailand, combined with a fairly strong southwest monsoon covering the Andaman Sea, Thailand, and the Gulf of Thailand.
Regarding sea conditions, the upper Andaman Sea will experience fairly strong winds from 19 to 21 August 2026, with waves 2 to 3 meters high, exceeding 3 meters where thunderstorms occur. The lower Andaman Sea and upper Gulf of Thailand will have waves about 2 meters high, rising above 2 meters during thunderstorms. Areas expected to face heavy rain may experience flash floods, flash floods, mudslides, waterlogging, and strong waves and winds between 18 and 21 August 2026, detailed as follows.
The Central Disaster Prevention and Mitigation Command Center, under the DDPM, has coordinated with 42 provinces in northern, northeastern, central, and southern regions—including regional disaster prevention centers in risk areas—to prepare for increased rainfall and heavy rain that may cause flooding. It has ordered officials to monitor weather, rainfall, and water levels closely, deploying disaster machinery teams to at-risk areas for prompt response and assistance.
Especially in areas with accumulated rainfall exceeding 90 millimeters in 24 hours and frequently flooded hotspots, water drainage should be expedited to minimize impact. Temporary shelters should be prepared to accommodate evacuees. For natural tourist sites, particularly caves and waterfalls, warnings should be issued and access restricted if there is risk of disaster.
In cases of strong waves and winds, relevant agencies are to issue warnings or install signals along coastlines prohibiting tourists from swimming. Fishermen, boat operators, and passenger vessel businesses should be alerted to exercise caution during navigation.
If conditions worsen, authorities should consider banning all navigation, stationing personnel to monitor risk areas and assist residents around the clock. Public communication should encourage close attention to official weather updates and advisories, and inform at-risk populations in advance to prepare and follow safety instructions.
During this period, residents are urged to continuously monitor weather conditions, warnings, water situations, and official news via the THA DISASTER ALERT app, the 'DDPM Incident Report 1784' Line account, or the emergency hotline 1784, available 24 hours for coordination and assistance.
Information courtesy of the Department of Disaster Prevention and Mitigation (DDPM) Facebook page.