Thai Meteorological Department Issues Heavy Rain Warning for 42 Provinces

On August 30, 2026, the Thai Meteorological Department (TMD) issued a weather alert for 42 provinces across Thailand. The forecast indicates an increase in rainfall, with heavy to very heavy downpours expected in parts of the upper North, upper Northeast, and the East. This weather pattern is attributed to a monsoon trough moving across the upper North and Northeast toward a low-pressure area in southern China, combined with a relatively strong southwest monsoon covering the Andaman Sea, Thailand, and the Gulf of Thailand.

Residents and travelers in these regions are advised to remain cautious of flash floods and forest runoff, particularly in low-lying areas and near hillsides. The TMD specifically warns against traveling through routes prone to recurring flooding.

Maritime conditions are also affected, with waves in the upper Andaman Sea reaching 2–3 meters, and exceeding 3 meters in thunderstorm areas. The lower Andaman Sea and upper Gulf of Thailand expect waves of approximately 2 meters, rising higher during storms. Small boats in the upper Andaman Sea are advised to remain ashore. While the TMD has identified the affected provinces, the specific duration of this intense weather system remains subject to ongoing monitoring. Travelers should check local updates before planning trips to mountainous or coastal areas.