
The Thai Meteorological Department (TMD) issued Advisory No 9 at 5am on October 11, 2026, adding Kanchanaburi to its very heavy rain risk list. Five provinces are at risk of very heavy rain on October 11, while isolated heavy rain is forecast for Bangkok and surrounding areas.
The TMD’s October 11–13 warning forecasts unsettled weather, with thundershowers, gusty winds, hail, possible lightning strikes and isolated heavy to very heavy rain. The affected regions on October 11 are the lower North, Central region including Bangkok and its vicinity, East and South.
The TMD forecasts isolated very heavy rain on October 11 in Kanchanaburi, Ratchaburi, Samut Songkhram, Phetchaburi and Prachuap Khiri Khan.
The TMD’s forecast for isolated heavy rain on October 11 covers:
The TMD’s regional warning focuses on the South on October 12–13. The province-level heavy rain forecast identifies the following areas:
The TMD attributes the October 11–13 conditions to a high-pressure system from China extending over upper Thailand, alongside easterly and southeasterly winds prevailing over the Northeast, East and Gulf of Thailand.
The southwest monsoon is prevailing over the Andaman Sea, while a monsoon trough lies across the upper South, according to the TMD.
The TMD warns that heavy and accumulated rainfall could trigger flash floods, river overflows and landslides, particularly near waterways at the foot of hills and in low-lying areas. Waterlogging and sudden runoff are also possible.
People in the affected areas should monitor TMD updates, prepare for possible flooding and take extra care when travelling. The department also advises against staying in open spaces, under large trees or near unstable billboards during storms.
Waves in the Andaman Sea and Gulf of Thailand could exceed 2 metres in areas with thundershowers, according to the TMD. Mariners are advised to navigate cautiously and avoid areas experiencing thundershowers.
Advisory No 9 (255/2026) was signed by Nattawut Dandee, deputy director-general acting as director-general of the TMD. The department’s next advisory is scheduled for 5pm on October 11.