People walk next to cars submerged in flood waters after heavy rain in Bangkok on September 26, 2026. [AFP]

Bangkok authorities declared on Saturday a disaster across all 50 districts of the Thai capital after continuous rain caused heavy flooding.

The designation, which gives local organisations authority to take action, came after the governor said almost 300 millimetres (11.8 inches) of rain had fallen since Thursday.

"The water keeps coming in. It's hard to go out now. It's like my waist level now," said Somkid Pheuk-ngam, 67, a vendor who lives near a canal just north of central Bangkok.

"I cannot go anywhere. I have been closing my shop for two days now," she told AFP, adding that while she often gets flooded: "I think this time is worse than the 2011 flood."

The rain has fallen almost continually since Thursday afternoon, flooding roads and swelling Bangkok's canals, sending water into many homes and restaurants alongside them, AFP reporters saw.

Bangkok Governor Chadchart Sittipunt said the east of the city was most impacted and warned more rain was forecast.

"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 said on social media.

"The risk areas are those who live near canals. Every canal is now filled," he said, urging residents to move their cars to higher ground.

He also urged bedridden patients depending on life-saving medical equipment to consider a temporary stay in hospital.

Widespread flooding across Thailand in 2011 killed more than 500 people and damaged millions of homes.