Thai disaster agency flags hail, heavy rain and flash-flood risks

Thailand's Department of Disaster Prevention and Mitigation (DDPM) has issued an alert over unsettled weather across upper Thailand on November 6–7, 2026, with thundershowers, gusty winds, hail and isolated heavy rain expected.

In its latest assessment, the department identified four factors requiring continued monitoring: rainfall, river levels, reservoir storage and high tides.

The DDPM also highlighted the risk of flash floods and runoff in low-lying areas across several provinces.

Tha Chin River remains above its banks

Water levels in parts of the Tha Chin River basin remain above riverbank levels, with flooding continuing in low-lying areas outside flood embankments and along the river in Suphan Buri and Nakhon Pathom.

The river's flow was reported at 129 cubic metres per second, with levels showing a downward trend.

Two dams exceed storage capacity

The DDPM reported that large and medium-sized reservoirs held a combined 83% of their total storage capacity.

Two dams, Nong Pla Lai and Thap Salao, had exceeded their storage capacity.

Four others were approaching full capacity: Naruebodindrachinta, Bang Phra, Mae Ngat Som Boon Chon and Srinagarind dams.

The department is also monitoring high tides expected between November 9 and 17, particularly from the morning until midday.

Flash-flood watch covers 18 provinces

The DDPM identified 18 provinces requiring continued vigilance over possible flash floods and runoff.

In the Central region, areas under observation include low-lying parts of Suphan Buri and Nakhon Pathom, along with Nakhon Nayok.

In the East, the provinces are Prachin Buri, Chachoengsao, Chon Buri, Rayong, Chanthaburi and Trat.

Southern provinces on the watchlist are Chumphon, Nakhon Si Thammarat, Songkhla, Pattani, Yala, Narathiwat, Phang Nga, Phuket and Krabi.

Residents affected by natural disasters can contact the DDPM's 24-hour disaster assistance hotline on 1784.