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Thailand Weather Forecast: May 25, 2026
Thailand is deep into its rainy season on May 25, 2026, with the Thailand Meteorological Department (TMD) warning of thundershowers across the entire country. A moderate southwest monsoon driving weather over the Andaman Sea, the Gulf of Thailand, and inland areas is the main culprit, and conditions are particularly active along the southern and eastern coasts. If you are on Koh Lanta or planning to travel around Thailand today, read on for a regional breakdown.
What's Driving the Weather
The southwest monsoon is in full swing, and the TMD expects rainy conditions to continue through October. May 25 is a fairly typical day for this time of year, but that does not mean you should take it lightly. Thundershowers bring fast-changing conditions, rough seas, and the possibility of localized flooding.
Southern Thailand – West Coast (Koh Lanta's Region)
This area, covering Ranong, Phang Nga, Phuket, and Krabi, is among the most active weather zones in the country today. Temperatures range from 23°C to 35°C. Wind speeds vary by location:
- North of Phang Nga: winds 20–35 km/h, wave heights around 2 metres
- South of Phuket (including Krabi and Koh Lanta): winds 15–35 km/h, waves 1–2 metres, rising above 2 metres during thundershowers
Swimming and water sports carry elevated risk today. All vessels are advised to proceed with caution and avoid areas where thunderstorms are developing. Ferry and boat services to and from the islands may face delays or cancellations, so check with your operator before heading to the pier.
Southern Thailand – East Coast
Surat Thani, Nakhon Si Thammarat, Phatthalung, Songkhla, Yala, and Narathiwat are all affected. Temperatures sit between 23°C and 37°C, with winds of 15–35 km/h and offshore wave heights of 1–2 metres.
Bangkok
Expect afternoon and evening thundershowers in the capital. Temperatures range from 26–28°C overnight to 35–37°C during the day, with southwesterly winds at 10–20 km/h. Flooding in low-lying areas is possible, so carry rain gear and allow extra time for getting around.
Northern Thailand
Provinces including Chiang Mai, Chiang Rai, Mae Hong Son, and others can expect heavy rain. Temperatures range from 24°C to 37°C. Trekking, outdoor tours, and mountain roads may be affected, so plan activities for the morning when conditions tend to be calmer.
Northeastern Thailand
Loei, Nong Khai, Bueng Kan, Chaiyaphum, Nakhon Ratchasima, and Ubon Ratchathani are in the forecast zone, with temperatures ranging from 24°C to 38°C and winds at 10–20 km/h.
Central Thailand
Provinces including Nakhon Sawan, Kanchanaburi, Ratchaburi, and Samut Songkhram face similar conditions, with temperatures between 24°C and 38°C.
Eastern Thailand
Nakhon Nayok, Chon Buri, Rayong, Chanthaburi, and Trat see winds of 15–35 km/h and coastal wave heights of 1–2 metres, climbing above 2 metres during thundershowers. Marine activities along this coast carry real risk today.
Tips for Today
- Plan outdoor activities for the morning and wrap up before the afternoon
- Check with ferry operators before traveling to or between islands
- Stay out of the water during storms and heed any warnings from local authorities
- Monitor local updates throughout the day as conditions can shift quickly
- Carry rain gear wherever you are in Thailand today
Information sourced from The Thaiger.