Persistent heavy rainfall over nearly 48 hours has triggered widespread flooding across Bangkok, Thailand's capital, prompting red alerts in the worst-affected areas and forcing some residents to evacuate their homes. Rain that began falling on Thursday afternoon continued almost without interruption through Saturday morning, overwhelming the city's canal network and submerging major roads.

Officials reported that accumulated rainfall exceeded 20 centimetres, filling Bangkok's major canals to capacity and sending floodwaters into the central and eastern parts of the city. Bangkok Governor Chadchart Sittipunt warned residents living near waterways that the risk was highest in their areas. "The rain keeps falling and we are doing our best. We are trying to pump the water out, but the water in canals are full," he wrote on social media. "Every canal is now filled." He urged residents with cars to move them to higher ground, and the city's public transport authority offered free use of MRT train park-and-ride car parks until 2 October as a temporary measure.

Photos and videos from major roads such as Phetchaburi Road showed vehicles stranded in deep water and commuters wading through knee-high floodwaters. Residents described difficult conditions. "The water keeps coming in. It's hard to go out now. It's like at my waist level now," said Somkid Pheuk-ngam, 67, a vendor living near a canal north of central Bangkok, who added that the situation felt worse than the catastrophic 2011 floods — a disaster that killed more than 500 people nationwide and damaged millions of homes. Across Thailand, more than 84,000 people in 21 provinces have been affected by flooding as of Saturday, particularly in the central region.

Thailand's Meteorological Department attributed the extreme weather to a strong low-pressure system over the central region combined with intensifying southwest monsoon conditions, warning that heavy rain would persist across most of the country through Sunday. Authorities also flagged risks of flash floods, mudslides, and river overflow in eastern, northeastern, and central Thailand. Governor Chadchart additionally advised residents caring for bedridden patients relying on life-saving medical equipment to consider moving them temporarily to hospital.

The scale of the flooding has raised concerns about Bangkok's long-standing vulnerability to seasonal inundation. The city, which sits on low-lying land in the Chao Phraya river delta, has invested heavily in drainage infrastructure since the 2011 disaster, but this week's event has tested those systems to their limits. Authorities continued pumping operations and cell-broadcast emergency alerts to residents in affected zones as forecasters offered little immediate relief.