Floods across Thailand have killed 31 people and affected about 4.14 million others since Sept 16, authorities said on Monday.

According to the Department of Disaster Prevention and Mitigation, nearly 3.52 million people in 26 provinces and the capital are still facing floods.

Thailand's Prime Minister Anutin Charnvirakul on Monday ordered agencies to speed up drainage, relief, and post-flood recovery as the Southeast Asian country braces for a new round of rain and high tides.

Chairing a meeting of the National Disaster Command Headquarters, Anutin said the overall situation was improving, with water levels in upstream areas starting to stabilize and fall.

Anutin instructed operators of full or nearly full reservoirs to release water immediately while protecting communities downstream. He also called for clearing blocked waterways and drains and pumping water out of inundated areas.

Heavy rain, thunderstorms, and strong gusts are forecast through Wednesday across much of the country, including Bangkok, the Department of Disaster Prevention and Mitigation said.