Flights to and from the NSC Bose International Airport (NSCBIA) here were disrupted because of overnight rain accompanied by strong winds.
"While some domestic flights from the city to other destinations were cancelled due to inclement weather, some incoming flights were diverted to different airports after they failed to land here amid gusty wind," NSCBIA Director Atul Dikshit told PTI.
He said details were still coming in about the cancellation and diversion of flights.
"We hope that operation of flights will become normal after the weather condition improves," he said."
National carrier Air India said five of its incoming flights could not land at the airport here because of gusty winds and were diverted to other destinations.
However, departure of all morning flights from here was normal till 8 am and there was no cancellation of flights by AI, a spokesman said.
While Delhi-Kolkata and Delhi-Mumbai flights were diverted to Delhi and Ranchi respectively, a flight from Port Blair was diverted to Agartala. A flight from Silchar to Kolkata had to land at Guwahati and a flight from Agartala to Kolkata had to go back to Agartala, the AI spokesperson said.
Only a flight from Hyderabad to Kolkata could land here this morning, he said.
Some private airlines cancelled their flights, airport sources said.
"Jet Aiways had to cancel some flights from Kolkata and five incoming flights had to be diverted to other destinations," the sources said.