TMD warns of flash floods amid heavy southern rain until October 28

The Thai Meteorological Department (TMD) has warned of heavy to very heavy rainfall in southern Thailand from October 24 to 28, 2026, raising concerns about flash floods, runoff and flooding in low-lying areas.

In a weather advisory issued at 5pm on Friday (October 23), the department forecast persistent rainfall throughout the five-day period, with heavy rain expected in many areas and exceptionally heavy downpours in some locations.

Residents have been advised to remain alert to flooding caused by accumulated rainfall, particularly in foothill communities near waterways, flood-prone areas and low-lying locations where water may collect.

Unsettled weather is also expected to affect upper Thailand between October 25 and 27, bringing thundershowers, gusty winds and isolated heavy rainfall.

The northeastern region is expected to experience the conditions first, followed by the North, Central region, Bangkok and surrounding provinces, and the East.

Residents in affected areas should take precautions against thunderstorms and strong winds, avoiding open spaces, large trees and unstable advertising hoardings.

The department attributed the changing weather conditions to a high-pressure system or cold air mass from China extending over upper Thailand and the South China Sea.

This system will strengthen easterly winds over Thailand and the Gulf of Thailand, while the monsoon trough extending across the South is expected to intensify, bringing additional rainfall.

Marine warning for the Gulf of Thailand and Andaman Sea

The department also warned of hazardous sea conditions, with waves exceeding two metres in areas experiencing thundershowers in both the Gulf of Thailand and the Andaman Sea.

Mariners have been advised to navigate cautiously and avoid sailing through thunderstorms.

Regional weather forecast for October 23–24

The department also released a 24-hour weather forecast covering the period from 6pm on October 23 to 6pm on October 24, with southern Thailand expected to experience the most widespread rainfall.

Southern Thailand's east coast is forecast to experience thundershowers covering 60% of the area, with isolated heavy rainfall in Surat Thani, Nakhon Si Thammarat, Phatthalung, Songkhla, Pattani, Yala and Narathiwat. Temperatures will range from 22–25°C at night to 33–35°C during the day, with variable winds of 15–30 km/h. Waves will be approximately one metre high, exceeding two metres during thundershowers.

Southern Thailand's west coast will also see thundershowers affecting 60% of the area, with heavy rainfall expected in Phuket, Krabi, Trang and Satun. Minimum temperatures will range from 24–26°C, with highs of 32–35°C. Northwesterly winds will reach 15–30 km/h, while waves will be around one metre high, rising above two metres in areas affected by thundershowers.

Eastern Thailand is expected to experience thundershowers across 40% of the region, mainly in Nakhon Nayok, Chachoengsao, Chonburi, Rayong, Chanthaburi and Trat. Temperatures will range from 24–26°C to 33–36°C, with easterly winds of 10–30 km/h. Offshore waves will generally remain below one metre but could exceed two metres during thundershowers.

Bangkok and surrounding provinces have a 40% chance of thundershowers, with minimum temperatures of 25–27°C and maximum temperatures of 33–35°C. Easterly winds are expected at speeds of 10–20 km/h.

Central Thailand will see thundershowers across 30% of the region, particularly in Saraburi, Phra Nakhon Si Ayutthaya, Kanchanaburi, Ratchaburi, Nakhon Pathom, Samut Sakhon and Samut Songkhram. Temperatures will range from 22–26°C to 34–36°C, accompanied by easterly winds of 10–20 km/h.

Northeastern Thailand is forecast to experience thundershowers in 10% of the region, mainly in Nakhon Ratchasima, Buriram, Surin, Sisaket and Ubon Ratchathani. Minimum temperatures will range from 22–25°C, while maximum temperatures will reach 34–36°C. Northeasterly winds are expected at 10–20 km/h.

Northern Thailand will also experience thundershowers affecting 10% of the region, mainly in Mae Hong Son, Tak and Phetchabun. Temperatures will range from 22–26°C to 34–36°C, with southeasterly winds of 10–20 km/h.

Public advised to monitor weather updates

The department encouraged residents to plan their daily activities and travel carefully during the affected period, particularly in areas vulnerable to flooding and severe weather.

The public should continue monitoring official weather forecasts and warnings as conditions develop.

Further information is available through the Thai Meteorological Department's website or its 24-hour telephone services on 02-399-4012-13 and 1182.