The Thai Meteorological Department (TMD) has officially announced the start of the rainy season following a series of downpours that have affected more than 60% of the country's upper regions over the past three days. This transition from summer, observed

In upper Thailand, the rainy season, brought over by southwest winds at about 1,500 meters elevation bringing moisture from the Andaman Sea, is anticipated to last until mid-October. Meanwhile, the southern regions, particularly the east coast, will face extended periods of rainfall that could persist until mid-January.
The department's immediate weather forecast stresses a concern for heavy rainfall across the North, Northeast, Central Plains, East, and the southern coast from May 21 to 24. The TMD has issued warnings for residents in these areas to prepare for heavy to very heavy rain, which could lead to runoff and potential flash flooding.
The change in wind direction at about 10,000 meters, now coming from the east, also contributes to these expected conditions. Residents and local authorities are advised to remain vigilant and take necessary precautions to mitigate the impact of the seasonal rains.