Thailand Meteorological Department Forecasts Heavy September Rains and Storm Risks

According to a report from Khaosod Online on August 20, 2026, the Thai Meteorological Department (TMD) has released its weather outlook for September 2026. The forecast indicates that Thailand will experience persistent rainfall, with thunderstorms expected across 60–80% of the country throughout the month. While overall rainfall is projected to be 10% below normal levels, the TMD warns that many areas remain at risk for heavy to very heavy downpours, which could lead to flash floods, forest runoff, and overflowing riverbanks.

For those living in or visiting Thailand, the TMD highlights that the southwest monsoon will periodically strengthen, causing rough sea conditions. Waves in the Andaman Sea and the upper Gulf of Thailand are expected to reach heights of 2 to 3 meters, while the lower Gulf may see waves between 1 and 2 meters. Furthermore, the agency notes a high probability of tropical cyclones moving from the South China Sea toward or across the country.

Travelers and residents are advised to monitor official TMD announcements closely, as weather patterns can shift rapidly. While the forecast provides a general outlook, specific localized warnings regarding storm paths and flood risks remain subject to change. It is essential to stay updated through official channels to ensure safety during this period of heightened weather activity.