Rising flood water forced Nakhon Si Thammarat airport to temporarily close Thursday, while land transport in many areas of the South remain paralysed due to widespread flooding.
The airport announced the temporary closure after a runway was flooded and water damaged the power system.
Airport director Suksawat Sukwanno said Thursday the turnpad of Runway No 19 was submerged and power and air navigation systems were out of order.
If the rain stops soon, the airport may reopen Friday.
In Hua Sai district, soldiers attached to the Nakhon Si Thammarat-based Military Circle 41 were sent to assist local authorities in handing out relief supplies to flood-ravaged victims in tambon Ramkaew.
Flat-bottomed boats loaded with relief bags and food supplies went to stranded communities in Moos 1, 4 and 5, with residents having gone without basic necessities for more than a week. Community roads were swallowed up by rising floods.
Water levels in the district have continued to rise as a result of persistent torrential rain. The flood situation has also been exacerbated by runoff from the nearby districts of Cha-uat and Chian Yai as well as from Ranot district in neighbouring Songkhla province.
Nakhon Si Thammarat is one of the worst hit southern provinces with monsoon storms battering several districts.
According to local officials, six residents have been killed and almost 460,000 others affected by flooding which has caused havoc in all 23 districts of the province since late last month.
The flooding has also forced a total of 287 schools to temporarily close.
In Prachuap Khiri Khan, the Provincial Disaster Prevention and Mitigation Office warned villagers to be on alert as heavy rain and storms could trigger landslides.
Strong winds and rough seas lashed coastal areas along Hua Hin beach and Prachuap Bay.
A red flag will be raised to warn people against going into the sea in case of dangerous waves.
The office is also working with the Marine Office 3 in supervising several coastal provinces along the Gulf of Thailand to provide warnings to owners of speed boats, tourist shuttle boats and fishing trawlers.
Meanwhile, Prime Minister Prayut Chan-o-cha is due to visit Muang and Kantang districts of Trang which were engulfed by flood water after the collapse of riverbanks on Sunday.
In tambon Bang Rak in Muang district, motorists were forced to make detours after a community road was partially destroyed by flash floods which opened a hole measuring 30 metres long and 2-3 metres deep along the road.
In the deep South, local authorities expedited efforts to provide an additional 200 relief-bags to flood-affected victims in Moos 3, 9 and 10 in tambon Lam Phu of Narathiwat’s Muang district. The villages have been cut off from the outside world due to flooding along community roads.
More heavy rain is forecast with warnings of landslides and further flooding issued in 10 southern provinces; Chumphon, Nakhon Si Thammarat, Narathiwat, Pattani, Phatthalung, Satun, Songkhla, Surat Thani, Trang and Yala.
Monsoon rain is predicted to continue pummelling the South - especially in Nakhon Si Thammarat, Phatthalung, Songkhla and Surat Thani - Friday.