Monsoon conditions leave most Thai regions under widespread rain
A monsoon trough and relatively strong southwest monsoon are bringing widespread rain, with very heavy falls in the North, East and the South’s west coast.
- A monsoon trough and a strong southwest monsoon are causing heavy to very heavy rainfall across most regions of Thailand.
- The weather advisory forecasts thunderstorms over 60-70% of most regions, with isolated very heavy rain expected in the North, East, and the South's west coast.
- Authorities have warned the public of potential flash floods and run-off, particularly in low-lying areas and near foothills.
- Mariners are advised to proceed with caution due to high waves of 2-3 meters in the Andaman Sea, with a warning for small boats to remain ashore.
The Thai Meteorological Department (TMD) warned at 5pm on Thursday (July 30, 2026) that heavy to very heavy rain would continue across parts of Thailand through the end of the day.
The advisory forecast isolated very heavy rain in the North, East and the South’s west coast, while isolated heavy rain was expected in the Northeast, Central region, Bangkok and surrounding provinces, and the South’s east coast.
A monsoon trough extended across the North and Northeast, while a relatively strong southwest monsoon prevailed over the Andaman Sea, Thailand and the Gulf of Thailand.
People were advised to watch for heavy to very heavy rain and accumulated rainfall that could trigger flash floods and run-off from forested areas, particularly on foothill slopes near waterways and in low-lying areas.
Waves in the upper Andaman Sea were expected to reach 2–3 metres and exceed 3 metres in thunderstorms.
Waves in the upper Gulf of Thailand and lower Andaman Sea were forecast at about 2 metres, rising above 2 metres in thunderstorms.
Mariners in the Andaman Sea and Gulf of Thailand were advised to proceed with caution and avoid areas affected by thunderstorms, while small boats in the upper Andaman Sea should remain ashore during the period.
For safety and to limit possible impacts, people were advised to plan their daily activities and travel carefully and to follow TMD announcements.
Updates are available at tmd.go.th or by calling 0-2399-4012-13 or 1182, 24 hours a day.
Thailand weather forecast: 6pm on Thursday (July 30, 2026) to 6pm on Friday (July 31, 2026)
North
- Thunderstorms are forecast across 70% of the region, with heavy rain in Mae Hong Son, Chiang Mai, Chiang Rai, Nan, Uttaradit, Tak, Kamphaeng Phet, Sukhothai, Phitsanulok and Phichit, and isolated very heavy rain in Phetchabun.
- Minimum temperatures of 22–26°C and maximums of 30–35°C are expected, with southwesterly winds of 10–20 km/h.
Northeast
- Thunderstorms are forecast across 70% of the region, with isolated heavy rain in Loei, Nong Khai, Bueng Kan, Nong Bua Lamphu, Udon Thani, Sakon Nakhon, Nakhon Phanom, Chaiyaphum, Khon Kaen, Nakhon Ratchasima, Buriram and Surin.
- Minimum temperatures of 23–25°C and maximums of 29–33°C are expected, with southwesterly winds of 10–20 km/h.
Central region
- Thunderstorms are forecast across 70% of the region, with isolated heavy rain in Nakhon Sawan, Uthai Thani, Lop Buri, Saraburi, Phra Nakhon Si Ayutthaya, Kanchanaburi, Ratchaburi, Nakhon Pathom and Samut Sakhon.
- Minimum temperatures of 24–26°C and maximums of 33–35°C are expected, with southwesterly winds of 10–25 km/h.
Bangkok and surrounding provinces
- Thunderstorms are forecast across 70% of the area, with isolated heavy rain.
- Minimum temperatures of 25–27°C and maximums of 32–35°C are expected, with southwesterly winds of 10–25 km/h.
East
- Thunderstorms are forecast across 70% of the region, with heavy rain in Prachin Buri, Sa Kaeo, Chachoengsao and Chon Buri, and isolated very heavy rain in Nakhon Nayok, Rayong, Chanthaburi and Trat.
- Minimum temperatures of 23–26°C and maximums of 29–34°C are expected, with southwesterly winds of 20–35 km/h.
- Waves are forecast at about 2 metres and above 2 metres in thunderstorms.
South (east coast)
- Thunderstorms are forecast across 60% of the region, with isolated heavy rain in Phetchaburi, Prachuap Khiri Khan, Chumphon and Surat Thani.
- Minimum temperatures of 22–26°C and maximums of 29–34°C are expected, with southwesterly winds of 15–35 km/h.
- Waves are forecast at about 1 metre, rising to 1–2 metres offshore and above 2 metres in thunderstorms.
South (west coast)
- Thunderstorms are forecast across 70% of the region, with heavy rain in Phang Nga, Phuket and Krabi, and isolated very heavy rain in Ranong.
- Minimum temperatures of 23–24°C and maximums of 28–33°C are expected.
- From Phang Nga northwards, southwesterly winds are forecast at 20–40 km/h, with waves of 2–3 metres and above 3 metres in thunderstorms.
- From Phuket southwards, southwesterly winds are forecast at 20–35 km/h, with waves of about 2 metres and above 2 metres in thunderstorms.
