TMD issues five-day heavy rain warning for October 21–25
Southern Thailand faces persistent rain, while Bangkok and other regions expect wetter weather and gusts, with flash floods possible
The Thai Meteorological Department (TMD) issued a fresh warning at 5am Thai time on Wednesday (October 21, 2026) for heavy to very heavy rain in parts of Thailand through October 25. Persistent downpours in the South and increased rainfall in several other regions could cause flash floods and sudden runoff.
Southern Thailand faces persistent rain through October 25
The TMD forecasts persistent rain in southern Thailand during October 21–25, with heavy to very heavy downpours in some areas.
Rainfall is also expected to increase in the lower Northeast, lower Central region including Bangkok and surrounding provinces, the East and upper South during October 21–25, according to the TMD. Strong gusts are forecast in some places.
The TMD warned that heavy and prolonged rainfall in parts of Thailand during October 21–25 could trigger flash floods and sudden runoff, particularly on foothill slopes and in low-lying areas. Residents should also beware of strong gusts.
Monsoon trough and southwest monsoon bring rain
The TMD attributed the wet conditions to a monsoon trough across the central part of southern Thailand and the southwest monsoon over the lower Andaman Sea.
A high-pressure system, or cold air mass, from China is expected to spread over the upper North, upper Northeast and South China Sea, according to the TMD. The system will bring easterly winds over Thailand and the Gulf of Thailand.
Thunderstorms could bring waves above three metres
Waves in thunderstorm areas of the Andaman Sea and Gulf of Thailand are forecast to exceed three metres during October 21–25, the TMD said. Boaters in both seas should proceed cautiously and avoid thunderstorms.
The TMD advised residents to plan daily activities and travel carefully during October 21–25 to reduce risks and possible disruption, and to keep following official weather warnings.
The TMD provides weather updates around the clock through its website and by telephone on 02-399-4012, 02-399-4013 and 1182. The next advisory is scheduled for 5pm Thai time on October 21.
