But the local weather office has said it is likely to continue until Saturday. All 14 districts of the state are under red alert as heavy rain continued in many parts of the state.
All rivers from northern district of Kasaragod to Thiruvananthapuram in the south are in spate.
The airport was flooded after shutters of both Cheruthoni and Mullaperiyar dams were kept open because of heavy inflow.
Chief Minister Pinarayi Vijayan will review the flood situation later Thursday as many areas remain without power and drinking water sparking fears of an epidemic outbreak, officials said.
More than 1.5 lakh people are now living in relief camps.
An incessant downpour battered Kerala again on Wednesday, resulting in 28 more deaths and more destruction and forcing authorities to issue a red alert across the southern state.
"Kochi airport is not operating flights as runway is flooded.We shall explore possibilities of smaller aircraft's landing at alternate authorised landing places, will ensure all rescue operations will get full assistance from aviation ministry, will coordinate all with state govt (sic)", he said in another tweet.More news: Pregnant Reality Star Lyric McHenry, 26, Dies of Suspected Drug Overdose
Rains also did not spare Thiruvanathapuram city with low lying areas being inundated, prompting residents to shift to relief camps. "In Kuttanad, we are anticipating a rise in water level, also in areas like Ernakulam, Alappuzha, Chengannur", the CMO said.
The airport at Nedumbassery near Kochi (Cochin International Airport - CIAL) caters to a significant number of more than 3mn Malayalis living overseas.
The state has also sought the services of additional Army personnel and helicopters and the prime minister has assured all help, Vijayan said.
Cochin International Airport had initially announced that operations would be suspended till Wednesday afternoon.
Operations at the Kochi airport have been suspended till August 18 and flights were being diverted to various airports.
A total of 33 dams were opened to release excess water. V.J. Kurien, managing director of Cochin International Airport Limited, explained the suspension of services was necessitated by increase in level of water as a result of flooding from the Periyar.
"Once the water recedes, it will take us 24 hours to clean up". Landslides have caused heavy damage and deaths in northern districts.