Update, September 28: Bangkok closed all city-run schools today to ease traffic and reduce the burden on parents as the flood recovery continues — five major canals (Prem Prachakon, Lat Phrao, Saen Saep, Prawet Burirom, Siri Watthana) remain at critical levels and 93 roads are still flooded. The city has opened 233 shelters with capacity for 15,000 people, and officials estimate 2-3 rain-free days are needed to drain roughly 223 million cubic meters of accumulated water. Separately, Nonthaburi (just northwest of Bangkok) declared disaster zones in two districts — Mueang Nonthaburi and Pak Kret, including Bang Phut and other riverside areas — as Chao Phraya River levels keep rising, with the same report noting continued flight delays and baggage backlogs at Suvarnabhumi and suspended service on some eastern rail routes.
Update, September 27: Bangkok’s governor has formally declared the city a disaster area as the flooding has escalated further, with at least 8 deaths reported nationwide and more than 174,000 households affected across the country. Suvarnabhumi and Don Mueang airports remain open but flights are delayed with baggage backlogs — CAAT is advising travelers to arrive at least 3 hours before departure, and Thai Airways and at least three other carriers are waiving change fees for flood-affected tickets. Some officials report conditions beginning to ease in parts of the city, though key canals remain at critical levels, so the situation is still developing.
Update, September 25: Thailand flood alerts have now produced real disruption in Bangkok itself, not just outlying provinces. The Thai Meteorological Department issued its ninth warning of the round, with heavy-rain coverage across roughly 80% of Bangkok, the Central region, and the East through September 27. Bangkok’s Khlong Sam Wa district recorded 105.5mm of rain on September 25, flooding Sai Mai, Bang Khen, and stretches of Vibhavadi Rangsit and Ngam Wong Wan roads. To the east, Sa Kaeo province logged 211mm and Trat 140mm in five hours, and industrial estates in Samut Prakan and Ayutthaya have been placed on their highest flood alert through September 27. Separately, flooding has caused serious disruption in Pattaya, including a boat-travel ban and a missing tourist — see our dedicated Pattaya flooding update for details if you have plans there.
Update, September 24: The alert has widened again — Thai authorities are now warning Bangkok plus 70 provinces, with the flash-flood and landslide watch for September 23-27 now explicitly including southern Andaman-coast tourist provinces (Phuket, Phang Nga, Ranong, Surat Thani, Songkhla, Chumphon, Narathiwat) alongside the north and northeast. As of the morning of September 24, 41 provinces remain on heavy-rain alert and 15 on very-heavy-rain alert. Thailand flood alerts covered more than 46 provinces starting September 20, 2026, before widening to 55 on September 21 and now 70. If you have travel planned anywhere in Thailand over the next few days — including the southern islands — it’s worth checking conditions before you go.
What’s Behind the Thailand Flood Alerts
A band of intense monsoon rain moved across Thailand starting September 20, prompting the Thai Meteorological Department to issue heavy rainfall warnings for 46-plus provinces, with 27 flagged for a higher-level flood and landslide alert through at least September 21. Local authorities in the affected areas have been telling residents and travelers in low-lying and hillside areas to monitor conditions closely.
Update: Alert Widens to 55 Provinces, Bangkok Included
The Thai Meteorological Department expanded its flood and landslide alert to 55 provinces for the 24-hour period from 6am on September 21, with the highest risk flagged in Nakhon Nayok and Prachin Buri. Six separate landslide and flood incidents were already logged nationwide on September 20, before the wider alert took effect. Small boats in the upper Andaman Sea have been advised to stay ashore as swells build to 2-3 meters. A further round of heavy rain and rough seas is now forecast for September 23 through 27, so this isn’t a one-day event — treat the whole week as unsettled.
Update, September 24: 70 Provinces Now Included, Southern Islands Added
The warning has widened again, now covering Bangkok and 70 provinces in total. The newly added flash-flood and landslide watch list includes, for the first time this round, southern Andaman-coast destinations popular with travelers: Phuket, Phang Nga, Ranong, Surat Thani, Songkhla, Chumphon, and Narathiwat. A small-craft advisory is also in effect for the upper Gulf of Thailand, with waves forecast at 2-3 meters (exceeding 3 meters during thunderstorms) through September 27. As of the morning of September 24, 41 provinces are on heavy-rain alert and 15 on very-heavy-rain alert, including Nakhon Ratchasima, Chon Buri, Rayong, and Trat — confirming this is an active, multi-day event rather than a single spike.
Where the Thailand Flood Alerts Matter Most for Travelers
The alerts started out skewed toward the north and northeast (areas like Chiang Mai, Chiang Rai, and provinces along the Mekong and its tributaries) plus the upper-central region and Bangkok, but as of September 24 they’ve expanded to cover southern beach destinations too — Phuket, Phang Nga, Surat Thani, and other Andaman and Gulf-coast provinces are now on the flash-flood and landslide watch list. Bangkok and Pattaya have now both seen real flooding impacts (see the September 25 update above), and travelers heading to the southern islands should still check conditions and factor in the small-craft advisory covering both the Andaman Sea and the upper Gulf.
What Travelers Should Do
Check the Thai Meteorological Department’s site or app for the latest province-by-province status before road trips or treks in the north, especially anything involving mountain roads, waterfalls, or river crossings. Avoid scheduling hikes or remote excursions in provinces under active landslide alerts until conditions clear. If you’re already in an affected area, follow guidance from your hotel or tour operator — flash floods in Thailand’s north can develop quickly during sustained heavy rain. If you’re headed to Phuket, Phang Nga, or other newly-included southern provinces, check ferry and speedboat schedules before island-hopping — the small-craft advisory covers both the Andaman Sea and the upper Gulf through September 27.
The Bigger Picture
These Thailand flood alerts reflect the monsoon season doing what it typically does in September, but the scale of this warning (46+ provinces) is broader than usual. Similar heavy-rain patterns have caused disruption elsewhere in the region this month, including flooding and landslides in Vietnam, so if your itinerary spans multiple Southeast Asian countries, it’s worth checking conditions at each stop rather than just your port of entry.
Update, September 29
Thailand’s nationwide flood death toll has risen to at least 10, up from 8, with roughly 700,000 people across about 329,000 households affected; floodwaters were reported slowly receding by September 28 after the weekend’s heaviest rain (CP24/AP). The Thai Cabinet declared special public holidays for state offices on September 28-29 in Bangkok, Nonthaburi, Pathum Thani, and Samut Prakan to ease travel for residents, with all eight Bangkok expressways made toll-free through September 29 (Human Resources Online). At Suvarnabhumi Airport, the baggage backlog worsened as flood-related staffing shortages kept many workers from reaching the airport — some Thai Airways passengers reported 6-10 hour delays — prompting the Royal Thai Air Force to deploy 69 personnel to help clear it; taxis were reportedly unable to reach central Bangkok as of September 28 (Khaosod English).
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