ONWR warns four northern provinces of heavy rain, flooding and landslides from July 23-25
The Office of the National Water Resources has warned of heavy rain in northern Thailand from July 23-25, with several areas at risk of flash floods, forest runoff and landslides.
The Office of the National Water Resources (ONWR) has issued a warning for heavy rain in northern Thailand, after its three-day risk forecast for July 23-25, 2026 showed several provinces could face accumulated rainfall from monsoon conditions.
The agency warned that affected areas may be at risk of flash floods, forest runoff and landslides.
Daily risk areas from July 23-25
July 23, 2026: Heavy rain of 35-90mm
- Chiang Mai: Omkoi district
- Tak: Tha Song Yang and Umphang districts
- Nan: Mae Charim district
- Mae Hong Son: Mae Sariang and Sop Moei districts
July 24, 2026: Heavy rain of 35-90mm
- Chiang Rai: Wiang Kaen district
- Chiang Mai: Omkoi district
- Tak: Tha Song Yang and Mae Sot districts
- Phayao: Chun, Chiang Kham, Chiang Muan, Dok Kham Tai and Pong districts
- Mae Hong Son: Sop Moei district
July 25, 2026: Very heavy rain of more than 90mm
- Chiang Rai: Mae Sai district
- Chiang Mai: Omkoi district
- Tak: Tha Song Yang district
- Mae Hong Son: Sop Moei district
Heavy rain of 35-90mm
- Chiang Rai: Mueang Chiang Rai, Chiang Khong, Phan, Mae Chan, Chiang Saen, Mae Suai, Wiang Pa Pao and Mae Fa Luang districts
- Chiang Mai: Chai Prakan, Chiang Dao and Phrao districts
- Tak: Mueang Tak, Sam Ngao, Mae Ramat, Mae Sot, Phop Phra and Umphang districts
- Nan: Tha Wang Pha district
- Phayao: Mueang Phayao, Chun, Chiang Kham, Dok Kham Tai, Pong and Phu Kamyao districts
- Lampang: Wang Nuea district
- Mae Hong Son: Mae Sariang district
Three-day accumulated rainfall warning
Based on the three-day accumulated rainfall forecast, ONWR warned that the highest-risk orange-zone areas could receive 150-200mm of accumulated rain.
The areas requiring close monitoring are:
- Omkoi district, Chiang Mai
- Tha Song Yang district, Tak
- Sop Moei district, Mae Hong Son
People in the risk areas are advised to closely follow water-situation updates and beware of flash floods, landslides, mudslides and flooding in low-lying areas.
Residents should move belongings to higher ground where necessary and plan travel carefully in advance.
Further water-situation updates are available from https://nationalthaiwater.onwr.go.th/
