Kathmandu's Air Today Is Making People Sick. Here Is the Number You Need to Know.

Step outside in Kathmandu today and take a deep breath. Actually — don't.

The air quality index right now is 124. That puts it in the "Unhealthy for Sensitive Groups" zone according to international standards. Children, elderly people, pregnant women and anyone with asthma or a heart condition should be limiting their time outdoors.

And this is a relatively okay day by Kathmandu standards.

Back in March 2026, the AQI hit above 200 — officially "Very Unhealthy." On that day, IQAir ranked Kathmandu as the single most polluted major city on the planet. Not in South Asia. In the world.

The numbers are staggering. Kathmandu's PM2.5 levels in 2024 averaged 45.1 micrograms per cubic metre. The WHO guideline is 5. That means the air Kathmandu residents breathe on an average day is nine times more polluted than what doctors consider safe.

Why is it this bad? A few reasons that stack up on each other.

The valley's shape is the first problem. Kathmandu sits in a bowl. When the air is calm, pollution has nowhere to go — it just sits there and builds. Add the emissions from an old fleet of diesel vehicles, nearby brick kilns that operate with almost no emission controls, construction dust from a city that has been under continuous development for years, and cross-border pollution drifting in from northern India, and you have a recipe for disaster.

Wildfires in the Chure region during March through May make everything worse every single year.

The current AQI is 124. Keep your windows closed. Wear a mask if you go outside. And if you have children or elderly family members at home — keep them inside today.

Check IQAir.com or Nepal's Department of Hydrology for live readings throughout the day.