Flood waters in the Thai capital of Bangkok have breached barriers at Don Muang Airport forcing it to close.
Hundreds of local residents who had been sheltering in the terminal building of the domestic airport have also been evacuated.
Suvarnabhumi Airport, the main international airport to the south-west of the city, is unaffected.
Thailand has seen the situation deteriorate rapidly in recent days, with flooding in several provinces north of the capital.
The cabinet approved more than $8 billion in loans to help flooded manufacturers, small and medium enterprises and independent businesses recover yesterday.
Four days of public holiday at the end of October were also declared to help communities recover from the floods.
Economists estimate the economic losses could reach more than $6 billion.
Monsoon season rains have led to nearly 800 deaths across south-east Asia - almost half in Thailand,
Cambodia, Burma, Vietnam, Laos and the Philippines have also been hit.