Thailand's Meteorological Department warns 36 provinces to expect heavy rain and potential flash flooding tomorrow, with the Andaman coastal and eastern regions facing particularly severe conditions from a southwestern monsoon system.
The Thai Meteorological Department has warned 36 provinces to prepare for heavy rainfall tomorrow with risks of flash floods and flash flooding, particularly in foothill areas. The department's 24-hour forecast for May 22, 2025, indicates continued heavy rain in the northern, upper northeastern, central, Bangkok metropolitan, and southern regions, with particularly heavy rainfall expected in the Andaman coastal areas and eastern regions. The moderate southwestern monsoon combined with southeasterly and southeasterly winds bringing moisture from the South China Sea across Thailand's upper regions, along with a low-pressure system over northern Vietnam, is driving the weather pattern. Residents should take precautions against heavy and accumulated rainfall, which may cause flash floods and flash flooding, especially in foothill areas near water channels and low-lying areas. Health care should also be maintained during this period of weather changes.
Wind and sea conditions in the Andaman Sea and Gulf of Thailand are moderate, with waves approximately 2 meters high in the upper Andaman Sea and upper Gulf of Thailand, and 1-2 meter waves in the lower Andaman Sea and lower Gulf of Thailand. Where thunderstorms occur, waves exceed 2 meters. Sailors in these areas should navigate with caution and avoid areas with thunderstorms.
Weather forecast for Thailand from 6 PM today to 6 PM tomorrow:
Northern Region – Thunderstorms affecting 60% of the area with heavy rain in some places, particularly in Mae Hong Son, Chiang Mai, Lampoon, Nan, Tak, Kamphaeng Phet, Phichit, Phitsanulok, and Phetchabun provinces. Low temperature 23-25°C, high temperature 32-36°C. Southwest wind 10-20 km/h.
Upper Northeastern Region – Thunderstorms affecting 40% of the area with heavy rain in some places, particularly in Loei, Nong Khai, Bueng Kan, Chaiyaphum, and Nakhon Ratchasima provinces. Low temperature 24-25°C, high temperature 33-36°C. Southwest wind 10-20 km/h.
Central Region – Thunderstorms affecting 70% of the area with heavy rain in some places, particularly in Nakhon Sawan, Lopburi, Saraburi, Kanchanaburi, Ratchaburi, Nakhon Pathom, Samut Songkhram, and Samut Sakhon provinces. Low temperature 25-26°C, high temperature 34-36°C. Southwest wind 10-20 km/h.
Eastern Region – Thunderstorms affecting 60% of the area with heavy to very heavy rain in some places, particularly in Nakhon Nayok, Prachuap Khiri Khan, Chachoengsao, Rayong, Chanthaburi, and Trat provinces. Low temperature 25-27°C, high temperature 30-35°C. Southwest wind 20-35 km/h. Sea waves approximately 2 meters high, exceeding 2 meters where thunderstorms occur.
Southern Region (East Coast) – Thunderstorms affecting 60% of the area with heavy rain in some places, particularly in Phetchaburi, Prachuap Khiri Khan, Chumphon, and Surat Thani provinces. Low temperature 23-25°C, high temperature 33-36°C. Southwest wind 15-35 km/h. Sea waves 1-2 meters high offshore, approximately 2 meters, exceeding 2 meters where thunderstorms occur.
Southern Region (West Coast) – Thunderstorms affecting 70% of the area with heavy to very heavy rain in some places, particularly in Ranong, Phang Nga, Phuket, and Krabi provinces. Low temperature 23-25°C, high temperature 32-35°C. From Phuket northward: Southwest wind 20-35 km/h. Sea waves approximately 2 meters high, exceeding 2 meters where thunderstorms occur.