31/08/2026
🇹🇭 Weather Forecast for Thailand
🗓️ Monday, 31 August 2026
⏰ 24-hour weather forecast from 00:00–24:00 today
📡 Updated from the latest Thai Meteorological Department announcement issued at 23:00 on 30 August 2026, and the latest water–disaster agency information available before 04:00
🚨 Key situation today: Thailand remains in a period of heavy to very heavy rain risk, especially in the eastern part of the Northern region, the upper Northeastern region, and the Eastern region. Bangkok and vicinity will have rain in about 60% of the area, with isolated heavy rain. The Thai Meteorological Department warns that accumulated rainfall may cause flash floods, forest runoff, and short-duration waterlogging.
🔴 Provinces requiring special monitoring for very heavy rain today: Chiang Rai, Phayao, Nan, Tak, Bueng Kan, Sakon Nakhon, Nakhon Phanom, Nakhon Nayok, Chanthaburi, and Trat. Heavy rain will also cover many other provinces in the Northern, Northeastern, Central, and Eastern regions.
🌊 The upper Andaman Sea will have waves 2–3 meters high and above 3 meters in thunderstorm areas. Small boats should remain ashore. The lower Andaman Sea and upper Gulf of Thailand will have waves about 2 meters high.
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🌏 General Weather Conditions
🌧️ The monsoon trough still lies across the upper Northern region and the upper Northeastern region, extending into a low-pressure cell over upper Vietnam. Meanwhile, the rather strong southwesterly monsoon prevails over the Andaman Sea, Thailand, and the Gulf of Thailand. These are the main factors bringing heavy to very heavy rain to many areas.
⚠️ The Thai Meteorological Department emphasizes caution over accumulated rainfall, especially in foothill areas, near waterways, low-lying areas, and roads with repeated flooding history. Flash floods, forest runoff, and short-duration waterlogging may occur even if rain does not fall all day in that area.
🚨 The latest heavy to very heavy rain warning checked was Warning No. 9 (176/2026), effective through 2 September 2026. The main risk areas include the western parts of the Northern and Central regions, the upper and eastern parts of the Northeastern region, and the Eastern region.
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⛈️ Regional Forecast: 7 Regions
🌳 Northern Region
🌧️ Thunderstorms are expected in 70% of the area.
🟠 Isolated heavy rain: Mae Hong Son, Chiang Mai, Lamphun, Lampang, Phrae, Uttaradit, Phitsanulok, Phichit, and Phetchabun
🔴 Isolated very heavy rain: Chiang Rai, Phayao, Nan, and Tak
🌡️ Minimum temperature: 23–27°C
🌡️ Maximum temperature: 28–33°C
💨 Southwesterly winds: 10–20 km/h
🚨 Chiang Rai–Phayao–Nan–Tak, including mountainous areas and upper river basins, require special monitoring because the new rainfall round is adding to soil moisture and accumulated rainfall from earlier days.
🌾 Northeastern Region — Isan
🌧️ Thunderstorms are expected in 70% of the area.
🟠 Isolated heavy rain: Nong Khai, Udon Thani, Kalasin, Mukdahan, Maha Sarakham, Chaiyaphum, Roi Et, Yasothon, Amnat Charoen, and Ubon Ratchathani
🔴 Isolated very heavy rain: Bueng Kan, Sakon Nakhon, and Nakhon Phanom
🌡️ Minimum temperature: 23–24°C
🌡️ Maximum temperature: 28–34°C
💨 Southwesterly winds: 10–25 km/h
💧 Areas along the Mekong River and its tributaries from Nong Khai–Bueng Kan–Nakhon Phanom, including the Songkhram River Basin, should continuously monitor water levels.
🌿 Central Region
🌧️ Thunderstorms are expected in 60% of the area, with isolated heavy rain in:
📍 Kanchanaburi
📍 Ratchaburi
📍 Lop Buri
📍 Saraburi
🌡️ Minimum temperature: 23–25°C
🌡️ Maximum temperature: 34–35°C
💨 Southwesterly winds: 10–25 km/h
⚠️ Kanchanaburi–Ratchaburi, especially the Tenasserim Range and mountain-fed runoff areas, should continue monitoring forest runoff and soil slips.
🌴 Eastern Region
🌧️ Thunderstorms are expected in 70% of the area.
🟠 Isolated heavy rain: Prachin Buri, Sa Kaeo, and Rayong
🔴 Isolated very heavy rain: Nakhon Nayok, Chanthaburi, and Trat
🌡️ Minimum temperature: 23–27°C
🌡️ Maximum temperature: 28–34°C
💨 Southwesterly winds: 20–35 km/h
🌊 Sea waves will be about 2 meters high and above 2 meters in thunderstorm areas.
🚨 Nakhon Nayok–Chanthaburi–Trat are very high-watch areas today, especially foothill areas, waterfalls, canals, fruit orchards, and low-lying communities.
🌊 Southern Region — East Coast
🌦️ Thunderstorms are expected in 40% of the area, mostly in Phetchaburi, Prachuap Khiri Khan, Chumphon, and Surat Thani.
🌡️ Minimum temperature: 23–26°C
🌡️ Maximum temperature: 32–35°C
🌊 From Surat Thani northward, waves will be 1–2 meters high and about 2 meters offshore.
🌊 From Nakhon Si Thammarat southward, waves will be about 1 meter high, 1–2 meters offshore, and above 2 meters in thunderstorm areas.
📍 For Songkhla, Pattani, Yala, and Narathiwat, these provinces are not in TMD’s main heavy-rain group today, but localized rain and high waves in thunderstorm areas remain possible.
🌴 Southern Region — West Coast
🌦️ Thunderstorms are expected in 40% of the area, mostly in:
📍 Ranong
📍 Phang Nga
📍 Phuket
📍 Krabi
🌡️ Minimum temperature: 23–27°C
🌡️ Maximum temperature: 32–34°C
🚨 From Phuket northward, southwesterly winds will be 20–40 km/h. Waves will be 2–3 meters high and above 3 meters in thunderstorm areas.
🌊 From Krabi southward, waves will be about 2 meters high and above 2 meters in thunderstorm areas.
🚫 Small boats in the upper Andaman Sea should remain ashore.
🏙️ Bangkok and Vicinity
🌧️ Thunderstorms are expected in 60% of the area, with isolated heavy rain.
🌡️ Minimum temperature: 25–26°C
🌡️ Maximum temperature: 32–35°C
💨 Southwesterly winds: 10–25 km/h
🚗 Short-duration heavy rain may cause waterlogging in low-lying spots and affect traffic. Travelers should check rain radar before departure and allow extra time.
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🌊 Marine and Wave Conditions
🚨 Upper Andaman Sea: Waves 2–3 meters high and above 3 meters in thunderstorm areas.
🌊 Lower Andaman Sea: Waves about 2 meters high and above 2 meters in thunderstorm areas.
🌊 Upper Gulf of Thailand: Waves about 2 meters high and above 2 meters in thunderstorm areas.
🚤 Boat operators should avoid thunderstorm areas, check radar before departure, and wear life jackets. Small boats in the upper Andaman Sea should remain ashore.
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💧 Water, Flooding, and Disaster Situation
💦 ThaiWater / Hydro-Informatics Institute has measured rainfall data through 29 August and rainfall forecasts for 30–31 August. Today’s monitoring should include 24-hour accumulated rainfall, water levels, and telemetry stations near the actual area, because heavy rainfall can be highly localized.
💧 The Office of the National Water Resources / National Thai Water has Thailand’s water situation for 30 August 2026, covering rainfall, water levels, water sources, water quality, and flash-flood / landslide early warning systems. This should be used to monitor upstream and low-lying areas today.
🚨 The National Disaster Warning Center published its latest disaster news and public-warning report for 30 August at 18:00. People should follow today’s new updates, Cell Broadcast alerts, and provincial announcements because area-specific warnings may change faster than national reports.
🚨 The Department of Disaster Prevention and Mitigation reported a rain and gusty-wind incident in Na Thon Subdistrict, Thung Wa District, Satun Province, on 30 August at 11:50, where a fallen tree damaged one house and injured one person. The incident has ended and damage assessment is underway.
🛰️ GISTDA’s Disaster Platform and geospatial systems should be used together with ground reports to check flood and runoff areas. Satellite data have different processing cycles from field reports, so one satellite image showing no detected area should not be interpreted as “no flooding” in all locations.
🔎 High-level water-risk watch areas today
🔴 Chiang Rai–Phayao–Nan–Tak
🔴 Bueng Kan–Sakon Nakhon–Nakhon Phanom
🔴 Nakhon Nayok–Chanthaburi–Trat
🟠 Also monitor Mae Hong Son–Chiang Mai–Uttaradit–Phitsanulok–Phetchabun, Nong Khai–Udon Thani–Mukdahan–Ubon Ratchathani, Kanchanaburi–Ratchaburi, and low-lying areas of Bangkok and vicinity.
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😷 Air Quality: PM2.5 / Air4Thai
🌿 Current weather conditions include frequent rain and fairly active monsoon winds, which generally help ventilate and wash out dust in many areas. However, AQI and PM2.5 values change hourly, so people should check the nearest station before outdoor activities.
🛰️ GISTDA’s PM2.5 monitoring system, which supports spatial monitoring, has data accessible through search up to 30 August. Live Air4Thai data should be checked directly by station. Values that do not match 31 August should not be reported as current readings.
📱 People should check the Pollution Control Department’s Air4Thai before exercising or working outdoors, especially children, older adults, pregnant women, and people with heart or respiratory diseases.
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🌅 Approximate Sunrise and Sunset Times
📝 Based on representative cities in each region. Actual times in each province may differ by several minutes.
🌳 Northern Region — Chiang Mai: 🌅 06:08 | 🌇 18:39
🌾 Northeastern Region — Khon Kaen: 🌅 05:55 | 🌇 18:22
🌿 Central Region — Nakhon Sawan: 🌅 06:06 | 🌇 18:32
🌴 Eastern Region — Rayong: 🌅 06:04 | 🌇 18:26
🌊 Southern Region — East Coast — Surat Thani: 🌅 06:14 | 🌇 18:33
🌴 Southern Region — West Coast — Phuket: 🌅 06:19 | 🌇 18:36
🏙️ Bangkok and Vicinity: 🌅 06:06 | 🌇 18:30
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🔭 7-Day Weather Outlook: 31 August–6 September 2026
📅 The latest official forecast from the Thai Meteorological Department covers 30 August–5 September, with 31 August–2 September still a high-watch period.
🚨 31 August–2 September: Thailand will continue to have increased rainfall, with isolated heavy to very heavy rain, especially in the western parts of the Northern and Central regions, the upper and eastern Northeastern region, and the Eastern region. The monsoon trough continues to work together with the rather strong southwesterly monsoon.
🌳 Northern Region: Until 2 Sep, rain in 60–80% of the area, with isolated heavy to very heavy rain. During 3–5 Sep, rain decreases to 40–60%, but isolated heavy rain remains possible.
🌾 Northeastern Region: Until 2 Sep, rain in 60–80% of the area, with isolated heavy to very heavy rain in the upper and eastern parts. During 3–5 Sep, rain remains 60–70%, with isolated heavy rain in the eastern part.
🌿 Central Region: Rain in 40–60% of the area throughout the period. On 31 August, isolated heavy rain remains possible in the western part.
🌴 Eastern Region: Rain in 40–60% of the area throughout the period, with isolated heavy rain. On 31 August, isolated very heavy rain remains possible, before intensity trends downward afterward.
🌊 Southern Region — East Coast: During 31 Aug–4 Sep, rain is expected around 30–40% of the area, while waves in thunderstorm areas may exceed 2 meters.
🌴 Southern Region — West Coast: Intermittent rain continues. The upper Andaman Sea will have strong waves early in the week, before the monsoon is expected to weaken after 2 September.
🏙️ Bangkok and Vicinity: Rain remains possible at times. Short-duration heavy rain can still create waterlogging. Hourly rain radar should be monitored.
🌤️ 3–5 September: The southwesterly monsoon is expected to weaken, but the monsoon trough will still lie across the Northern region and upper Northeastern region. The Northern, Northeastern, and Eastern regions may still have isolated heavy rain. This should not be interpreted as rain stopping immediately.
📌 6 September is outside the latest 7-day forecast period issued on 30 August. People should wait for a new forecast before identifying specific risk provinces.
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🛡️ Safety Recommendations
🏠 Flood-risk areas: Move documents, medication, electrical appliances, and valuables to higher ground. Prepare drinking water, dry food, a flashlight, power bank, life jacket, and keep Cell Broadcast alerts enabled.
⛰️ Mountain areas: Avoid waterfalls, hiking, caves, and camping near streams in heavy-rain areas, especially Chiang Rai, Phayao, Nan, Tak, Nakhon Nayok, Chanthaburi, and Trat, because forest runoff may come from rainfall upstream far away.
🚗 Road users: Reduce speed, turn on headlights, increase following distance, beware of landslides, falling rocks, and fallen trees, and never drive through fast-flowing water of unknown depth.
🚤 Boat operators: Small boats in the upper Andaman Sea should remain ashore. All vessels should avoid thunderstorm areas and wear life jackets at all times.
🌾 Farmers: Clear drainage channels, check paddy-field embankments, aquaculture ponds, farm structures, and electrical systems, reinforce fruit trees, and move livestock, machinery, fertilizer, and chemicals away from low-lying areas.
😷 Health: Check Air4Thai before outdoor activities. Avoid walking through floodwater without protective footwear, and beware of leptospirosis, athlete’s foot, dengue fever, food poisoning, and diseases from contaminated water.
📞 Important Hotlines: 🌦️ Thai Meteorological Department 1182 • 🚨 DDPM 1784 • 🌿 Pollution Control Department 1650 • 🚑 Emergency Medical Services 1669 • 🚔 Police 191 • 🚒 Fire 199
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🔍 Reference Sources
🌦️ Thai Meteorological Department — Latest 24-hour weather forecast issued at 23:00 on 30 August 2026
🚨 Thai Meteorological Department — Heavy to very heavy rain warning, Warning No. 9, effective through 2 September 2026
📅 Thai Meteorological Department — 7-day forecast for 30 August–5 September 2026
💧 ThaiWater — National Water Data Archive and district-level rainfall monitoring system
🚨 National Disaster Warning Center — Disaster news and public-warning report for 30 August 2026
🚨 Department of Disaster Prevention and Mitigation — Public-disaster situation report and rain / gusty-wind incident in Satun Province
💦 Office of the National Water Resources — National Thai Water
🛰️ GISTDA — PM2.5 monitoring system and geospatial data
😷 Pollution Control Department — Air4Thai for station-level AQI and PM2.5 monitoring
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