Thai Meteorological Department Issues Heavy Rain Warning for 39 Provinces

On July 30, 2026, the Thai Meteorological Department (TMD) issued a weather warning for 39 provinces across Thailand, forecasting heavy to very heavy rainfall covering 70% of these areas. According to Khaosod Online, this weather pattern is driven by a monsoon trough passing through the northern and northeastern regions, combined with relatively strong southwest winds affecting the Andaman Sea and the Gulf of Thailand.

For residents and travelers, the TMD warns of potential flash floods and forest runoff, particularly in low-lying areas and regions near mountain slopes. The maritime conditions are also affected; the upper Andaman Sea is experiencing waves between 2 and 3 meters, with heights exceeding 3 meters in thunderstorm areas. The lower Andaman Sea and the upper Gulf of Thailand are seeing waves of approximately 2 meters, rising above 2 meters during storms.

Small boats in the upper Andaman Sea are advised to remain ashore. Mariners in all affected areas are urged to exercise extreme caution and avoid navigating through thunderstorm zones. While the forecast provides a 24-hour outlook, the duration of these conditions remains subject to further updates from the department. Residents in the affected 39 provinces should monitor local news for specific evacuation or safety instructions as the situation develops.