The Civil Aviation Authority of Vietnam closed Cat Bi Airport in the northern city of Hai Phong for a day Thursday after a runway was found cracked, possibly due to the heat.
A heat wave has blanketed the region, with the city recording over 39°C (102°F) that day.
The airport is expected to reopen Friday after the problem is fixed, according to the CAAV.
It said airport staff discovered the runway's asphalt cracked at one end at nearly 3 p.m. after Vietjet Air airplane took off with 157 passengers for Ho Chi Minh City.
Technicians sent to inspect the crack concluded that it had been caused by the heat.
Authorities then ordered 12 flights that were scheduled to land at Cat Bi to fly to Hanoi instead.
However, by the time the crack was discovered, 12 flights had departed or landed without incident, according to the CAAV.
Earlier this month a heat wave took temperatures in the central region to around 40 degrees Celsius and in the northern region to 39 degrees.