TMD issues Typhoon Ragasa Warning No 5, heavy rainfall expected in Thailand

At 4pm on Tuesday (September 23), the Thai Meteorological Department issued an update on Typhoon Ragasa, which is located in the upper South China Sea at coordinates 20.6°N latitude and 116.6°E longitude, with maximum sustained winds near the centre of approximately 195 km/h.

The storm is moving west-northwest at a speed of 20 km/h and is expected to approach Hong Kong and then pass along the southern coast of China before moving into the Gulf of Tonkin on September 25, 2025. The storm will weaken into a tropical storm before making landfall in northern Vietnam. 

It is forecast to dissipate rapidly due to cold air from China spreading over the region from September 25 to 26, 2025. This storm will not enter Thailand.

Impact of Typhoon Ragasa

The influence of Typhoon Ragasa has strengthened the monsoon trough extending over northern and northeastern Thailand, as well as the southwest monsoon covering the Andaman Sea, Thailand, and the Gulf of Thailand. From September 23 to 26, this will lead to increased rainfall across northern, northeastern, central, and eastern regions, including Bangkok and its vicinity, with heavy to very heavy rainfall in many areas.

Residents in the affected areas are advised to be cautious of the risks associated with heavy and accumulated rainfall, which may lead to flash floods, landslides, and overflowing rivers, particularly in areas near hillsides, waterways, lowland areas, and flood-prone regions.

Coastal conditions

The Andaman Sea and the upper Gulf of Thailand will experience stronger waves. The upper Andaman Sea could see waves as high as 2–3 metres, and in areas with thunderstorms, waves could exceed 3 metres. Mariners are advised to exercise caution, and small boats in the upper Andaman Sea should avoid going out from September 24 to 26, 2025.

Further updates

The public is urged to follow announcements from the Meteorological Department closely. Information can be accessed through the Department’s website or by calling 0-2399-4012-13 or 1182, available 24 hours a day.

Issued on September 23, 2025, at 5pm.

The next update will be issued on September 23, 2025, at 11pm.

Thailand Weather Forecast by the Meteorological Department: 6pm Tuesday (September 23) to 6pm Wednesday (September 24)

Northern Region

Thunderstorms are expected in 70% of the area, with heavy rainfall in some parts, particularly in Mae Hong Son, Chiang Mai, Lampang, Lamphun, Tak, Sukhothai, Kamphaeng Phet, Phitsanulok, Phichit, and Phetchabun. Minimum temperatures will range from 22–25°C, with maximum temperatures between 30–33°C. Winds will be variable, at 5–15 km/h.

Northeastern Region

Thunderstorms are expected in 70% of the area, with heavy rainfall in some parts, particularly in Sakon Nakhon, Nakhon Phanom, Khon Kaen, Kalasin, Mukdahan, Maha Sarakham, Roi Et, Yasothon, Amnat Charoen, Surin, Si Sa Ket, and Ubon Ratchathani. Minimum temperatures will range from 23–25°C, with maximum temperatures between 31–34°C. Winds will be variable, at 10–20 km/h.

Central Region

Thunderstorms are expected in 60% of the area, with heavy rainfall in some parts, especially in Nakhon Sawan, Uthai Thani, Lopburi, Saraburi, Kanchanaburi, and Ratchaburi. Minimum temperatures will range from 23–26°C, with maximum temperatures between 33–35°C. Winds will come from the southwest at 10–20 km/h.

Bangkok and Vicinity

Thunderstorms are expected in 70% of the area, with heavy rainfall in some parts. Minimum temperatures will range from 25–27°C, with maximum temperatures between 32–35°C. Winds will come from the southwest at 10–20 km/h.

Eastern Region

Thunderstorms are expected in 70% of the area, with heavy rainfall in some parts, particularly in Nakhon Nayok, Prachin Buri, Chachoengsao, Chanthaburi, and Trat. Minimum temperatures will range from 23–28°C, with maximum temperatures between 30–34°C. Winds will come from the southwest at 20–35 km/h. The sea will have waves up to 2 metres high, with waves greater than 2 metres in areas with thunderstorms.

Southern Region (East Coast)

Thunderstorms are expected in 20% of the area, mainly in Phetchaburi, Prachuap Khiri Khan, and Chumphon. Minimum temperatures will range from 22–26°C, with maximum temperatures between 32–36°C. Winds will come from the southwest at 15–35 km/h. The sea will have waves up to 1 metre high, with waves between 1–2 metres offshore. In areas with thunderstorms, waves will be higher than 2 metres.

Southern Region (West Coast)

Thunderstorms are expected in 20% of the area, mainly in Ranong and Phang Nga. Minimum temperatures will range from 24–26°C, with maximum temperatures between 31–34°C. From Phang Nga upwards, winds will come from the southwest at 20–35 km/h. The sea will have waves up to 2 metres high, with waves greater than 2 metres in areas with thunderstorms. From Phuket downwards, winds will come from the southwest at 15–35 km/h. The sea will have waves up to 1–2 metres high, with waves greater than 2 metres in areas with thunderstorms.