Thailand faces intensified rainy season with heavy rains and flood risks across 21 provinces

The Thai Meteorological Department warns of worsening monsoon conditions bringing heavy rain, floods, and hazardous sea conditions, impacting travel and safety across the country.

Thailand’s rainy season is set to intensify again today, with the Thai Meteorological Department warning of heavy rain across 21 provinces and the eastern seaboard facing the highest risk of very heavy downpours. For travellers, that means a greater chance of flooded roads, delayed journeys and rough seas, especially if you are heading to coastal destinations or planning island transfers.

The weather pattern is being driven by a strengthened monsoon trough stretching across Myanmar, Laos and upper Vietnam, alongside a strong south-westerly monsoon over the Andaman Sea, Thailand and the Gulf. The department says this combination should bring widespread showers to much of the country, with the upper North, the North-east and the East most exposed to sudden bursts of rain and localised flooding.

In practical terms, visitors should be especially cautious in Chanthaburi and Trat, where very heavy rain is possible, and in low-lying or hillside areas where flash flooding and run-off can develop quickly. The Thai Meteorological Department has also warned of landslide risks near waterways and in areas with steep ground, and has told boat operators to avoid thunderstorms. Small boats in the upper Andaman Sea are advised to stay ashore.

Sea conditions are also a concern for anyone travelling by ferry or speedboat. The department says waves in the upper Andaman Sea may reach two to three metres, rising above three metres in storms, while the eastern waters could also become hazardous during thundery weather. Around Bangkok and nearby provinces, thunderstorms are forecast over a wide area, so travellers should allow extra time for road journeys and keep an eye on official weather updates before heading out.