Bangkok has been hit by around 300-320 mm of rain over a few days, approaching the city’s long-term September rainfall average of 335.9 mm
Flooding has disrupted transport and aviation, with Thai authorities warning of heavy rain and CAAT arranging U-Tapao as a full-time alternate airport for flights affected by weather at Suvarnabhumi and Don Mueang
The airport disruption has also created a major baggage backlog, with Thai Airways working to clear luggage from 52 affected flights while further flight delays and cancellations have followed
Bangkok is dealing with widespread flooding after heavy rain pushed accumulated rainfall in parts of the capital above 300 mm in about 1½ days, according to Thai authorities, as airport operations were disrupted and airlines dealt with delayed baggage.
Bangkok Governor Chadchart Sittipunt said the capital had experienced continuous heavy rain since Thursday afternoon, with some areas recording around 300 mm of accumulated rainfall. He said the volume was unusually high and comparable to major rainfall events associated with storms in the past.
The Thai Meteorological Department had warned of heavy to very heavy rain across Bangkok and surrounding areas, citing an active low-pressure system moving through central Thailand and a strengthening southwest monsoon. It warned that accumulated rainfall could cause flash floods and overflowing waterways.
Nearly A Month’s Rain
The scale of the rainfall can be seen against Bangkok’s normal climate.
Thailand’s Meteorological Department records show that Bangkok Metropolis receives an average of 335.9 mm of rain in September over the 1991-2020 reference period. The figure for September is the highest monthly average in the year for the Bangkok station.
That means the more than 300 mm recorded during the recent spell amounts to almost 90% of the city’s long-term September average in roughly 1½ days.
The rainfall has overwhelmed drainage systems in several areas. Bangkok authorities said water remained high in a number of canals, while roads and residential communities were affected by overflowing waterways.
Flights Disrupted
The deluge has also disrupted air travel through Bangkok’s two main airports, Suvarnabhumi and Don Mueang.
Thailand’s Civil Aviation Authority said persistent rain had affected visibility and air-traffic management, causing delays and raising the possibility that some flights would need to divert to alternate airports for safety. CAAT asked passengers to allow extra travel time and check flight status with their airlines before leaving for the airport.
On Monday, CAAT said it had arranged for U-Tapao International Airport to operate as a full-time alternate airport until October 4 to handle flights that could not land at Suvarnabhumi or Don Mueang because of adverse weather.
Baggage Piles Up
At Suvarnabhumi, the disruption has extended beyond delayed flights.
Thai Airways said on Tuesday that baggage from 52 flights operated on Saturday and Sunday was still being delivered to passengers who had registered their details. The airline said it had deployed additional staff and resources to sort and deliver the delayed baggage.
Thai Airways also said 34 flights were delayed on Monday. CAAT said airlines must continue providing assistance to passengers affected by weather-related delays or cancellations under Thailand’s passenger-protection regulations, including food and drink, communication assistance and, where applicable, rebooking or refunds.
Flooding Continues
Bangkok authorities said water was still standing on a number of major roads, including parts of Ekkamai, Ngam Wong Wan, Vibhavadi Rangsit, Ramkhamhaeng, Lat Krabang and Chaeng Watthana.
Chadchart said the city’s drainage system could pump between 1,000 and 1,200 cubic metres of water per second, but that it could take two to three days to clear accumulated water if there was no substantial additional rainfall.
The meteorological department has forecast that rainfall will gradually ease as the low-pressure system moves westward, but authorities have urged residents to continue monitoring conditions as further rain could slow drainage and worsen flooding.













