Kathmandu Valley air turns unhealthy as dry season begins

Air quality across the Kathmandu Valley fell to unhealthy levels on Thursday morning as the post-monsoon dry season set in, according to IQAir data cited by the Kathmandu Post. The Swiss group collects readings from monitoring stations around the world.

Mid-Baneshwar recorded the highest PM2.5 concentration at 153 micrograms per cubic metre. Shantichowk in Bhaktapur followed at 151, Tarakeshwar at 147, Ranibari at 145, Teku at 139, Gaushala Chowk and Chhetrapati at 138 each, and Balaju at 134.

Under the US Environmental Protection Agency's Air Quality Index, a PM2.5 reading of 101 to 150 is unhealthy for sensitive groups, who may suffer health effects. A reading of 151 to 200 is unhealthy for everyone.

PM2.5 particles measure less than 2.5 micrometres across. They pass the nose and throat to reach the lungs and can enter the bloodstream, and they stay suspended in the air long enough to be inhaled again and again. The World Health Organization recommends an annual average of no more than 5 micrograms per cubic metre and a 24-hour average of 15.

Two Nepali border towns recorded worse readings than any station in the valley. Butwal and Dhangadhi each measured 160 on Thursday morning, according to the Kathmandu Post.

Bhupendra Das, an air quality expert, said the coming weeks are likely to be worse. "This is a peak harvesting season of paddy crops both in India and in Nepal, and stubble burning has already started," he said. "The worst days are yet to come, as we have done so little to check the air pollution in the country."

The Kathmandu Post reported that authorities have done little to fill potholes, control road dust or campaign against stubble and waste burning, and that pollution in the valley often reaches hazardous levels during the dry season. "The health costs of worsening air quality will be far greater than the public realises," Das said.

A new UNICEF report, Growing Up in a Climate Hotspot: The Risks Shaping the Lives and Future of Nepal's Children, estimates that 9.9 million children in Nepal are exposed to unhealthy levels of air pollution. The same report says 7.3 million children face drought, 5.7 million face extreme heat, 2.9 million face rainfall-triggered landslides and 2.4 million face several high-intensity climate hazards at once.

A World Bank report published in 2025, Towards Clean Air in Nepal: Benefits, Pollution Sources, and Solutions, found that air pollution has become the leading risk factor for death and disability in Nepal, ahead of malnutrition and tobacco use. It estimated that polluted air cuts life expectancy by 3.4 years for the average Nepali and causes about 26,000 premature deaths a year.

The bank linked air pollution to 75 percent of chronic obstructive pulmonary disease cases in the country, 46 percent of strokes, 44 percent of ischaemic heart disease, 41 percent of lower respiratory infections, 38 percent of lung cancer, 30 percent of neonatal conditions such as low birth weight and preterm birth, and 20 percent of diabetes.