Morning fog and haze have been severely affecting flight operations in Nepal, particularly in the Terai region, with visibility dropping below operational standards. According to reports, several airports, including Gautam Buddha International Airport in Bhairahawa, have experienced significant delays over the past week.
Delays in International Flights
Last Thursday, a Thai Air Asia flight from Bangkok had to circle above Bhairahawa for almost an hour due to poor visibility. Morning flights scheduled at Gautam Buddha International Airport are frequently delayed, with operations starting only after 11 AM when visibility improves, said airport manager Pratap Babu Tiwari.
Impact on Domestic Airports
Kathmandu’s Tribhuvan International Airport has also faced slight disruptions due to morning fog. However, Terai-based airports such as Biratnagar, Janakpur, Simara, Bharatpur, and Nepalgunj are the most affected, with some flights operating behind schedule.
Weather Observations
According to the Meteorological Forecasting Division, the increase in fog and haze during the winter mornings is common. Meteorologist Sanjiv Adhikari explained that dense fog and mist are particularly prevalent in the eastern and central Terai regions. While the hilly and Himalayan regions enjoy better visibility, ranging from 9 to 10 kilometers, Terai areas struggle with less than 1 kilometer of visibility in some cases.
Visibility Standards and Meteorological Analysis
Adhikari emphasized that global standards classify visibility below 1 kilometer as fog, while 1–5 kilometers is categorized as haze. Currently, the Terai region is experiencing a mix of both, creating operational challenges for airlines. No immediate rainfall is expected, and prolonged air pollution is contributing to the haze.
Flight Resumptions and Adjustments
Tribhuvan International Airport spokesperson Rinji Sherpa stated that although flights in Kathmandu remain largely unaffected, delays in opening regional airports have disrupted the flight schedule. Bhairahawa and Simara airports were the last to resume operations today, with Gautam Buddha Airport reopening at 12:50 PM.
The weather department predicts partly cloudy conditions in the Koshi and Gandaki hill regions, with a possibility of light rain in isolated areas. Despite the disruptions, flight schedules are expected to stabilize as visibility improves throughout the day.