Air Pollution in Kathmandu, Nepal: Updated Information

Current Status of Air Pollution in Kathmandu

As of April 2025, Kathmandu’s air quality remains poor despite recent rainfall. On April 13, PM2.5 levels reached 39 μg/m³ and PM10 at 75 µg/m³ in some areas, exceeding the World Health Organisation’s (WHO) safe limit of 15 μg/m³. 

While rain since April 9 (Wednesday) has provided minor relief by settling dust and reducing short-term particulate matter, pollution still remains high due to leftover smoke from wildfire and vehicle emissions.  

Earlier this year, the AQI reached a hazardous 384 μg/m³, making Kathmandu the most polluted city globally. This rise in pollution has been attributed to widespread wildfires and prolonged dry conditions. 

While writing this article, the air pollution in Kathmandu remains at PM2.5, i.e, fine particles (≤ 2.5 µm) at 58.3 µg/m³ and PM10, i.e, coarse particles (≤ 10 µm) at 179.9 µg/m³, which is still unhealthy. To see live updates on Kathmandu’s air pollution, you can visit different websites like IQAir. 

Past 10-Year Air Quality Index of Kathmandu

​According to The Kathmandupost, in 2024, Kathmandu was already regarded as the world’s most polluted city. Over the past decade, this capital city has faced significant air quality challenges. 

Between 2015 and 2019, the average PM2.5 concentrations were around 48 µg/m³, exceeding the WHO-recommended 15 µg/m³ limit. However, pollution spiked in subsequent years, particularly during the dry months of March to May. 

In early 2021, forest fires caused PM2.5 levels to peak at hazardous levels, with maximum hourly averages reaching 371 µg/m³. By November 2023, the same soared to 154 µg/m³, ranking Kathmandu as the seventh most polluted city globally. 

In April 2024, the Air Quality Index (AQI) hit 192, placing the city in the ‘Unhealthy’ category. Similarly, in 2025, the situation worsened, with PM2.5 levels reaching the highest record of 384 µg/m³, due to extensive wildfires and stagnant atmospheric conditions.

Major Causes of Air Pollution in Kathmandu Valley

Several factors make air quality worse in the valley. However, the study conducted by K4DD found that the primary causes include urbanisation, brick kilns, vehicular emissions, and transboundary pollution. Other causes, such as industrial activities, wildfires, crop burning, and waste burning, also contribute to this pollution.

Health Impacts

Exposure to high levels of air pollution has been linked to various health issues such as respiratory illness, cardiovascular diseases, and skin allergies.

• Increase in Respiratory Illnesses: Hospitals report increased cases of asthma, bronchitis, COPD, and other respiratory diseases due to poor air quality. There is a high chance of an asthma attack for those who already have it.
• Cardiovascular Concerns: Prolonged exposure to polluted air also increases the risk of heart-related conditions such as heart attack and stroke.
• Eye Irritations: Frequent cases of conjunctivitis (pink eye), dry eyes, and other eye-related issues due to smoke and dust.
• Increased Mortality Rates: Air pollution contributed to approximately 8.1 million premature deaths in 2021 worldwide, as it reduces life expectancy by 4-5 years on average.
• Skin allergies: Pollutants can cause or exacerbate skin problems such as eczema, psoriasis, and acne. Excess exposure can cause allergic reactions, resulting in rashes, itching, and inflammation.
• Pregnancy Complications: Exposure to polluted air during pregnancy is associated with outcomes such as low birth weight and preterm birth.