Scores of flights were affected due to bad weather conditions on Monday.

Lack of rainfall for a long time and the absence of strong winds has been blamed for the rise in the pollution levels, which caused a haze in the morning, according to experts.

“As we are in the midst of the winter season, the temperatures would decline further, meaning that the problem of haze will be there in the coming days,” said Barun Paudel, senior divisional meteorologist at the Meteorological Forecasting Division under the Department of Hydrology and Meteorology. “Due to the absence of rainfall and strong winds, the pollution levels have also increased, which is the reason for the haze in Kathmandu and other places in the country.”

All flights from Kathmandu to Simara and Janakpur were cancelled on Monday due to inclement weather conditions, airlines executives said. Similarly, most of the airports across the country didn’t operate until noon, forcing scores of flights to be rescheduled or delayed, affecting thousands of travellers.

Most of the districts in the Tarai region have been witnessing a thick fog in the morning, which is causing disturbances in the vehicular movements.

Lack of rainfall for a long time has been blamed for the worsening air quality in the Valley, which reached unhealthy levels for sensitive groups on Monday afternoon.

The country has not witnessed rainfall since the end of September. The Department of Hydrology and Meteorology has predicted low rainfall and above-average temperatures in most parts of the country between December 1, 2022 and February 28, 2023.

Meteorologists say that there is no weather system in sight, which could cause rainfall within a period of the next two weeks.

“Clouds would come, but they won't cause rainfall,” said Paudel. “Light snowfall could occur in the high mountainous areas, but rainfall is unlikely this week and the next week.”

The sky will be clear during the night, which causes a decline in the minimum temperature in the morning. Experts say the minimum temperature will decline in the morning as the sky will be clear at night. They suggested that the general public should not come out of their houses ealy in the morning if possible, keep children warm and wear a face mask while going out to lessen the adverse effects of air pollution.

On Monday, the Kathmandu Valley’s air quality index reached 137. As per the United States Environment Protection Agency’s air quality index, when air pollutant PM2.5 reaches 151 to 200 μg/m3, air quality is considered unhealthy; everyone may experience problems, with sensitive groups experiencing more severe effects. When it exceeds 300 μg/m3, it is considered “hazardous” for everyone and may prompt emergency condition alerts.

Hospitals in the Kathmandu Valley reported an uptick in cases of respiratory illnesses, including severe pneumonia, asthma and others.

“The number of patients suffering from respiratory illnesses have increased 50 percent in the last one and half months,” said Dr Ashesh Dhungana, a pulmonologist who is also a critical care physician at Bir Hospital. “Around 80 percent of our patients are elderly people, but the young people are also found to be suffering from pneumonia and asthma.”

According to doctors, most of the patients suffering from respiratory illness visit the hospitals only when they become seriously ill. They say that the worsening air quality of Kathmandu Valley is among the reasons behind a sharp increase in respiratory problems.