DDPM Warns 70 Provinces Nationwide and Bangkok to Monitor Flash Floods and Flash Flooding

Department of Disaster Prevention and Mitigation (DDPM) Issues warnings to 70 provinces nationwide and Bangkok to monitor for flash floods and flash flooding during 23 - 27 September 2026.

On 23 September 2026, Mr. Theeraphat Kachamat, Director-General of the Department of Disaster Prevention and Mitigation, stated that the DDPM, as the Central Disaster Prevention and Mitigation Command Center (CDPMCC), has been monitoring weather conditions and risk factors. Concurrently, the Meteorological Department issued a heavy to very heavy rainfall warning across Thailand (effective 23 - 27 September 2026), bulletin no. 2 (218/2569) announced on 22 September 2026 at 05:00, indicating heavy rain in many areas and very heavy rain in some locations, initially affecting the lower Northeast and Eastern regions, with other regions impacted subsequently.

This is due to a strong low-pressure system near the coast of central Socialist Republic of Vietnam moving over the lower Northeast, East, Central regions, including Bangkok and its vicinity. Additionally, the southwest monsoon is intensifying over the Andaman Sea, Thailand, and the Gulf of Thailand. Waves and winds in the Andaman Sea and Gulf of Thailand will strengthen, with wave heights in the upper Gulf reaching 2 - 3 meters, and exceeding 3 meters in areas experiencing thunderstorms.

Furthermore, the Office of National Water Resources issued announcement no. 5/2569 on 21 September 2026, warning of flash floods, flash flooding, and riverbank overflow from 22 - 26 September 2026. Areas prone to flash floods, flash flooding, landslides, and urban flooding due to inadequate drainage are identified for monitoring between 23 - 27 September 2026, as follows.

Areas to monitor for flash floods, flash flooding, landslides, and urban flooding.

• All provinces in the North, Northeast, and Central regions.
• Seven provinces in the South: Chumphon, Surat Thani, Songkhla, Ranong, Phang Nga, Phuket, and Narathiwat.

Areas to monitor for strong waves and winds.

• In the Central region, six provinces: Chonburi (Mueang Chonburi, Si Racha, Ko Sichang, Bang Lamung, and Sattahip districts), Rayong (Mueang Rayong, Ban Chang, Klaeng districts), Chanthaburi (Naiyai Am, Tha Mai, Laem Sing, and Khlung districts), Trat (Mueang Trat, Laem Ngop, Khlong Yai, Ko Chang, and Ko Kut districts), Phetchaburi (Mueang Phetchaburi, Ban Laem, Tha Yang, and Cha-am districts), and Prachuap Khiri Khan (all districts).
• In the South, three provinces: Chumphon (Mueang Chumphon, Pathiu, Sawi, Thung Tako, Lang Suan, and La-ngu districts), Surat Thani (Mueang Surat Thani, Chaiya, Tha Chana, Tha Chang, Phunphin, Don Sak, Kanchanadit, Ko Samui, and Ko Pha-ngan districts), and Nakhon Si Thammarat (Mueang Nakhon Si Thammarat, Khanom, Sichon, Tha Sala, Pak Phanang, and Hua Sai districts).

Areas to monitor for rapid water level rises, riverbank overflow, and flooding in low-lying areas along main rivers and tributaries include the Moei, Yuam, and Mae Sariang rivers in Mae Hong Son; Wang Thong River in Phitsanulok; Phachi River in Ratchaburi; Nakhon Nayok River in Nakhon Nayok; Prachinburi River in Prachinburi; Phra Sathing and Phra Prong canals in Sa Kaeo; Chanthaburi River in Chanthaburi; Kaper Canal in Ranong; and Sai Buri and Golok rivers in Narathiwat.

Regarding flood risk downstream of the Chao Phraya Dam, it is forecasted that water inflow from the upper basin will pass through the dam at approximately 1,500 cubic meters per second, causing water levels to rise by 0.75 - 1.25 meters. This will impact flood-prone lowland areas outside the dikes in Chai Nat (Sapphaya district), Sing Buri (In Buri district), Ang Thong (Mueang Ang Thong and Wiset Chai Chan districts), Phra Nakhon Si Ayutthaya (Sena, Phak Hai, Bang Ban, Phra Nakhon Si Ayutthaya, Bang Pa-in, and Bang Sai districts), and Pathum Thani (Mueang Pathum Thani and Sam Khok districts).

Therefore, the Central Disaster Prevention and Mitigation Command Center (CDPMCC) under DDPM has coordinated to notify 70 provinces nationwide and Bangkok, including regional disaster prevention and mitigation centers, to prepare for heavy rainfall that may cause flooding. Officials have been instructed to closely monitor weather, rainfall, and water conditions, and to deploy operation teams with public disaster machinery at risk areas for prompt response and assistance. Special emphasis is on frequently flood-prone zones and areas currently facing flood situations, urging full-capacity water drainage to minimize flood impact.

For natural tourist attractions, especially caves and waterfalls, if risks arise, warnings and area closures should be issued to prevent public entry. In cases of strong waves and winds, relevant agencies should issue announcements or install warning signals along coastlines, strictly prohibiting tourists from swimming during rough sea conditions. Fishermen, vessel operators, and passenger boat operators must exercise increased caution, and if conditions worsen, navigation bans should be considered. Additionally, agencies are coordinating to prepare temporary shelters, food, drinking water, and essentials to accommodate evacuees in case of flooding.

The public is urged to continuously monitor weather conditions, warnings, water situations, and official announcements. Updates can be accessed via the "THAI DISASTER ALERT" application and assistance requests can be made through the Line account "DDPM Report 1784" or the 24-hour safety hotline 1784 for coordination and support.

Thanks to the Facebook page of the Department of Disaster Prevention and Mitigation (DDPM).