Vietnam Airlines flight VN215 from Hanoi to Ho Chi Minh City made about eight holding loops before diverting to Phu Quoc Airport, according to Flightradar24 data.
Similarly, Vietjet flight VJ853 from Taichung, Taiwan, to Ho Chi Minh City had to circle before diverting to Cam Ranh Airport later that afternoon.
Aircraft were forced to hold because of bad weather at Tan Son Nhat Airport (Photo: Flightradar24).
At Tan Son Nhat's air traffic control centre, controllers recorded a series of flights entering holding patterns as they queued to land. Controllers worked continuously to manage the aircraft waiting to approach the airport.
Between 4.10 pm and 8 pm, about seven flights were diverted to alternative airports after being unable to land at Tan Son Nhat. Many other flights also had their departures delayed while airlines waited for weather conditions to improve.
For flights diverted to alternative airports, crews waited for conditions to improve before flying back to Tan Son Nhat. The late arrival of aircraft also caused subsequent departures from Tan Son Nhat to be delayed in a knock-on effect.
Air traffic congestion caused by bad weather has occurred repeatedly at Tan Son Nhat since late September, particularly on days of heavy rain in Ho Chi Minh City. Thunderstorms can reduce pilots' visibility, making it unsafe for aircraft to approach and land.
The Southern Regional Hydro-Meteorological Centre forecast moderate to heavy rain, with some areas receiving very heavy downpours, from 7 pm on October 7 to 7 pm on October 9.
Rainfall is expected to reach 70-140mm across most areas, with some locations receiving more than 150mm.