# Thailand monsoon flooding and southern preparedness > Live situation record from CLSTR: https://clstr.news/situations/thailand-monsoon-flooding > Updated: 2026-08-19T06:36:01.000Z. Sources: 18. Developments: 23. The southwest monsoon remains intense, maintaining widespread heavy-to-very-heavy rain warnings across Thailand. On August 5, the Thai Meteorological Department (TMD) forecasted that heavy rain would affect 60–70% of the country, with the strongest downpours expected in northeastern provinces such as Nong Khai, Udon Thani, and Ubon Ratchathani. While tropical storm Kujira was not expected to enter Thai waters, its presence in the South China Sea, combined with a monsoon trough, contributed to waves of 2–3 meters in the Andaman Sea. In Nakhon Phanom, heavy monsoon rains caused significant flooding, submerging homes, businesses, and roads. The Mekong River rose to 10.78 meters; although this remains below the 12-meter overflow warning level, the elevated water has hindered the drainage of runoff from local tributaries and city systems. In response, Governor Adisak Noisuwan and Mayor Niwat Jiawiriyaboonma ordered a multi-agency response, utilizing eight large water pumps and distributing sandbags via disaster prevention officials and soldiers. By mid-August, the TMD issued further warnings for heavy rain and potential flash floods effective August 13. Intense downpours were expected to impact Northern Thailand—specifically Chiang Rai, Mae Hong Son, and Chiang Mai—through August 15. On August 9, the Thai government issued directives to governors in 14 southern provinces to prepare for potential flooding and droughts under the direction of Prime Minister and Minister of Interior Anutin Charnvirakul. By August 19, Deputy Prime Minister Yotsanan Wongsawat issued urgent directives to governors in Nan, Phayao, and Lamphun to prepare for potential flooding and flash floods. Measures include monitoring high-risk zones, utilizing the Cell Broadcast system, and preparing KA-32 helicopters for evacuations and relief in hard-to-reach areas. ## Timeline ### 2026-08-19: Thailand orders flood preparedness in Nan, Phayao, and Lamphun Thailand's Deputy PM Yotsanan Wongsawat has ordered Nan, Phayao, and Lamphun provinces to prepare for flash floods and heavy rain through August 2026 using Cell Broadcast alerts and emergency helicopters. 2 sources. https://clstr.news/cluster/thailand-orders-flood-preparedness-in-nan-phayao-and-lamphun ### 2026-08-19: Thailand weather warning issued for heavy rain and flooding Thailand faces warnings for heavy to very heavy rain, flash floods, and forest runoffs through August 21, particularly in the North and Northeast, alongside high seas in the Andaman Sea. 2 sources. https://clstr.news/cluster/thailand-weather-warning-issued-for-heavy-rain-and-flooding ### 2026-08-17: Thailand weather warning issued for heavy rain and flash floods Thailand faces warnings for heavy to very heavy rain, flash floods, and potential river overflows from August 18-21 due to monsoon activity affecting the North, Northeast, East, and Bangkok. 5 sources. https://clstr.news/cluster/thailand-weather-warning-heavy-rain-and-flood-risks-expected ### 2026-08-14: Thailand weather alert: Heavy rain and flash flood warnings Thailand faces heavy rain and flash flood warnings due to a monsoon trough and strong southwest monsoon, with high waves reported in the Andaman Sea. 7 sources. https://clstr.news/cluster/thailand-weather-warning-heavy-rain-and-flash-flood-risks ### 2026-08-12: Thailand issues heavy rain and flash flood warnings Thailand faces widespread heavy rain and flash flood warnings due to a strong monsoon. In Chiang Rai, severe erosion has caused a vital bridge collapse, prompting emergency repair requests. 5 sources. https://clstr.news/cluster/thailand-issues-heavy-rain-and-flash-flood-warnings ### 2026-08-09: Thailand orders flood preparedness in 14 southern provinces The Thai government has ordered 14 southern provinces to prepare for flooding and drought, coordinating multi-agency technology use to manage water resources and emergency shelters. 2 sources. https://clstr.news/cluster/thailand-orders-flood-preparedness-in-14-southern-provinces ### 2026-08-08: Nakhon Phanom flooded due to heavy monsoon rains Heavy monsoon rains have caused flooding in Nakhon Phanom, Thailand, submerging homes and roads, while authorities warn of widespread flash flood risks across the country. 4 sources. https://clstr.news/cluster/nakhon-phanom-flooded-due-to-heavy-monsoon-rains ### 2026-08-04: Thailand Braces for Heavy Rain and Flood Risk as Monsoon Intensifies Thailand's weather service warns heavy rain will affect 60‑70% of the country on Aug 5, with flash‑flood and landslide risks and 2‑3 m waves in the Andaman Sea; nearby tropical storm Kujira heads toward the PH. 2 sources. https://clstr.news/cluster/thailand-braces-for-heavy-rain-and-flood-risk-as-monsoon-intensifies ### 2026-07-30: Thailand braces for heavy rain and flash floods across 44 provinces Thailand's meteorology agency warns heavy rain and flash floods across 44 provinces, with high waves up to 2 m; public urged to stay cautious. 2 sources. https://clstr.news/cluster/thailand-braces-for-heavy-rain-and-flash-floods-across-44-provinces ### 2026-07-27: Thai Meteorological Department warns of heavy rain across Thailand through July 30 Thailand’s Meteorological Department warned of heavy to very heavy rain nationwide from July 27‑30, urging caution over flash floods, landslides and high seas, especially for small vessels. 2 sources. https://clstr.news/cluster/thai-meteorological-department-warns-of-heavy-rain-across-thailand-through-july-30 ### 2026-07-24: Pattaya Flash Floods Disrupt Roads after Heavy Rain Heavy rain on July 23 caused flash flooding in Pattaya, Thailand, inundating a railway‑side road and stranding vehicles; water receded within an hour and officials are upgrading drainage ahead of further rains. 2 sources. https://clstr.news/cluster/pattaya-flash-floods-disrupt-roads-after-heavy-rain ### 2026-07-23: Thailand Issues Nationwide Heavy Rain and Flood Warnings for Late July Thailand alerts 61 provinces and Bangkok to heavy rain, flash floods and rough seas from July 26‑30, urging residents to avoid dangerous areas. 4 sources. https://clstr.news/cluster/thailand-issues-heavy-rain-warning-for-july-2630-2024 ### 2026-07-21: Thailand faces severe monsoon rains and hazardous sea conditions Intensifying monsoon brings heavy rain to northern Thailand, flash‑flood risk, Bangkok thunderstorms, and waves over two metres in coastal waters. 2 sources. https://clstr.news/cluster/thailand-faces-severe-monsoon-rains-and-hazardous-sea-conditions ### 2026-07-18: Thailand faces heavy rain and flash‑flood warnings Thailand's meteorological department warned of heavy rain, thunderstorms and flash‑flood risk across the east, north, northeast, central and south, with sea waves exceeding 2 metres. 3 sources. https://clstr.news/cluster/thailand-faces-heavy-rain-and-flashflood-warnings ### 2026-07-12: Thai Weather Agency warns of heavy rain and 4‑meter seas across southern and central Thailand Thailand's meteorological agency warns of heavy rain, flash‑flood risk and up to 4‑meter seas in southern, central and eastern regions from July 13‑15, urging caution for vessels and travelers. 3 sources. https://clstr.news/cluster/thai-weather-agency-warns-of-heavy-rain-and-4meter-seas-across-southern-and-central-thailand ### 2026-07-09: Thailand warns of heavy rain and high seas as monsoon intensifies Thailand's weather agency warned of heavy rain, flash‑flood risk and 2‑4 m waves across several provinces from July 11‑15 as the monsoon intensifies, reinforced by Typhoon Bavi near China. 4 sources. https://clstr.news/cluster/thailand-warns-of-heavy-rain-and-strong-seas-as-monsoon-intensifies ### 2026-07-07: Heavy Rain Forecast Triggers Flood Warnings Across Northern and Northeastern Thailand Thailand's weather service warns of heavy rain, thunderstorms and flash‑flood risk in the north and northeast, with moderate to strong sea waves along the coast. 2 sources. https://clstr.news/cluster/heavy-rain-forecast-triggers-flood-warnings-across-northern-and-northeastern-thailand ### 2026-07-05: Thailand prepares for heavy rain as Storm Maysak impacts north and east Storm Maysak brings heavy rain to northern and eastern Thailand on July 5‑6, 2024, prompting agricultural aid measures and marine warnings. 2 sources. https://clstr.news/cluster/thailand-prepares-for-heavy-rain-as-storm-maysak-impacts-north-and-east ### 2026-07-02: Thailand warns of heavy rain and high seas across 54 provinces Thailand's meteorological agency warned of heavy rain in 54 provinces, flash‑flood risk and 2‑3 m seas, urging boaters to stay ashore. 2 sources. https://clstr.news/cluster/thailand-warns-of-heavy-rain-and-high-seas-across-54-provinces ### 2026-06-27: Thailand braces for heavy rains and flooding as monsoon intensifies Thailand's weather agency issued a heavy‑rain warning for June 28‑July 3, expecting intensified monsoon rains, flash‑flood risks, high coastal waves and possible commuter disruptions. 2 sources. https://clstr.news/cluster/thailand-braces-for-heavy-rains-and-flooding-as-monsoon-intensifies ### 2026-06-25: Heavy rain and thunderstorms forecast across Thailand as tropical storm Me Kha moves toward Japan Thai forecasts call for heavy rain, thunderstorms and 1‑2 m waves across most of Thailand on June 26‑27, while tropical storm Me Kha heads toward Japan. 2 sources. https://clstr.news/cluster/thailand-faces-heavy-rain-and-thunderstorms-as-monsoon-intensifies ### 2026-06-25: Bangkok heavy rain floods Bang Khen, crippling traffic Bangkok’s Bang Khen district saw 71 mm rain, flooding major roads and causing traffic jams; officials deployed pumps and urged commuters to avoid affected routes. 2 sources. https://clstr.news/cluster/bangkok-heavy-rain-floods-bang-khen-crippling-traffic ### 2026-05-31: Thailand hit by heavy monsoon rains, flooding Bangkok and 14 provinces Heavy monsoon rains on May 31 flooded Bangkok and prompted a flood watch for 15 Thai provinces, with some areas expecting over 100 mm of rain in 12 hours, raising flash‑flood and transport concerns. 2 sources. https://clstr.news/cluster/thailand-hit-by-heavy-monsoon-rains-flooding-bangkok-and-14-provinces --- Cite as: Thailand monsoon flooding and southern preparedness. CLSTR, https://clstr.news/situations/thailand-monsoon-flooding