Thailand Braces for Heavy Rain Sept 21-27
Thailand's Meteorological Department warns of heavy to very heavy rain across much of the country September 21-27, with the most intense rainfall expected September 23-27 in the North, Northeast, central, eastern, and upper Southern regions
The Meteorological Department issued a seven-day regional weather forecast for September 21-27, 2025.
September 21-22: The North, lower Northeast, central region including Bangkok and surrounding areas, the East, and eastern Southern Thailand will continue to experience heavy rain in some areas. A high-pressure system and cold air mass from China covering the upper North and upper Northeast is weakening, while a monsoon trough continues to pass through the lower central, upper South, and eastern regions, moving into a strong low-pressure system over the central South China Sea. The southwest monsoon is moderate, covering the upper Andaman Sea and upper Thailand. Waves in the upper Andaman Sea and upper Gulf of Thailand are 1-2 meters high, exceeding 2 meters in thunderstorm areas. Fishermen are advised to navigate carefully and avoid thunderstorm zones.
September 23-27: The lower North, lower Northeast, central, eastern, and upper Southern regions will experience heavy to very heavy rainfall in many areas. A strong low-pressure system near central Vietnam's coast will move into Thailand along the monsoon trough passing over upper Thailand, while the southwest monsoon intensifies over the Andaman Sea, South, and Gulf of Thailand. Waves in the upper Gulf will be relatively strong at 2-3 meters, exceeding 3 meters in thunderstorm areas. The upper Andaman Sea and lower Gulf will see waves around 2 meters, exceeding 2 meters in thunderstorm zones.
Warnings: From September 23-27, people in the lower North, lower Northeast, central, eastern, and upper Southern regions should be alert to dangers from heavy to very heavy accumulated rainfall, which may cause flash floods and flash flooding, particularly in foothill areas near waterways and low-lying zones. All fishermen should navigate with caution and avoid thunderstorm areas. Small boats in the upper Gulf should remain ashore during September 23-27.
Regional Seven-Day Forecast (September 21-27, 2025):
North: Thunderstorms in 60-70 percent of the area with heavy rain in some places throughout the period. Very heavy rain in some lower northern areas September 25-26. East winds 10-20 km/h. Low 22-27°C, high 29-36°C.
Northeast: September 21-22: Thunderstorms in 60-70 percent of the area with heavy rain in some lower areas. September 23-27: Thunderstorms in 70-80 percent with heavy to very heavy rain in some places. East winds 10-20 km/h. Low 23-26°C, high 28-35°C.
Central: September 21-23: Thunderstorms in 60-70 percent with heavy rain in some places. September 24-27: Thunderstorms in 70-80 percent with heavy to very heavy rain in some places. Variable winds 10-20 km/h. Low 22-27°C, high 30-35°C.
