Heavy Rain Warning Covers Bangkok as Monsoon Trough Moves North

Thailand's Meteorological Department has issued a warning for heavy to very heavy rain across several regions from Sunday, October 18, through October 25, 2026.

The rain is being driven by a monsoon trough moving northward over the central and southern parts of the country.

Regional timeline

• October 18–20: Steady rain in the South and East, with some areas expected to receive heavy to very heavy downpours.
• October 21–25: Rainfall increases in the lower Northeast, the Central region (including Bangkok and nearby provinces), the East, and the upper South. Some areas may see heavy to very heavy rain, along with scattered gusty winds.

Bangkok and the surrounding Central provinces are specifically expected to get heavy rain and strong gusts from October 21 to 25.

Risks to watch for

Prolonged rainfall could trigger flash floods, sudden runoff from higher ground, and mudslides, particularly on foothill slopes near waterways and in low-lying areas. Residents are advised to avoid roads that flood repeatedly, since short-term flooding can develop quickly in low-lying spots.

What's driving the weather

At first, the weather is shaped by a monsoon trough over the lower South, along with the southwest monsoon over the lower Andaman Sea. The trough is then expected to shift north across the central South. At the same time, a high-pressure system or cold air mass from China is forecast to extend over the upper North, the upper Northeast, and the South China Sea.