Thailand braces for heavy rain and storms amid intensifying monsoon

The Thai Meteorological Department warns of widespread heavy rainfall and stormy conditions across Thailand, with potential flooding and marine hazards from 18 September due to an active monsoon system.

Thailand is set for another day of unsettled weather, with the Thai Meteorological Department warning of heavy rain across much of the country on 18 September. The system is being driven by a monsoon trough stretching across the lower North, the central region and the North-east, alongside a fairly strong south-west monsoon over the Andaman Sea, Thailand and the Gulf.

The department said Bangkok would see widespread thundershowers and isolated heavy downpours, with temperatures ranging from 24C to 35C. In the capital and surrounding central provinces, showers are expected to be widespread enough to disrupt travel, while the north and North-east face the added risk of isolated very heavy rain in several provinces.

The heaviest falls are forecast in parts of the North, North-east, East and the south-west coast, where the department has warned of possible very heavy rain in areas including Uttaradit, Phitsanulok, Phetchabun, Loei, Khon Kaen, Nakhon Ratchasima, Chanthaburi, Trat, Chumphon, Surat Thani, Phang Nga, Phuket and Ranong. The warning follows earlier alerts from the department covering 17 to 20 September, which said heavy to very heavy rain could affect wide parts of Thailand over several days.

Marine conditions are also expected to deteriorate, particularly in the Andaman Sea. Waves may reach around two metres or higher in thundershowers in the east, while the west coast could see waves of two to three metres, rising above three metres during storms. The department has urged people living near waterways, foothills and low-lying areas to watch for flash floods, overflows and landslides.