Heavy rain flooded roads and caused traffic chaos as Thailand moved into its annual rainy season.

Footage shows ankle-deep deluge slowing down drivers on the Ratachada Road in Bangkok on Wednesday morning, May 17.

An overnight downpour filled the streets with water forcing many residents to wade through the deluge.

The Thai Meteorological Department said Thailand had entered its rainy season around the second week of May and it will last until mid-October.

Soaring temperatures reaching 35 degrees Celsius are often followed by powerful tropical storms with thunder, lightning, rain and flash floods which cause rivers to flow faster and become dangerous.

Neighbouring countries in Southeast Asia such as Malaysia, Indonesia and the Philippines are reaching the start of their tropical monsoon rainy season.