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Nepal · Tier 2
530 days · 2024–2026 · 5 sensors
Moderate confidenceSeasonal historical data — not for today's readings. For current air quality: IQAir ↗ · Methodology →
Independent modelled estimate for reference. Our data uses station sensors which may cover different years and locations. Methodology →
Berkeley Earth conversion: 22.0 µg/m³ PM2.5 ≈ 1 cigarette/day. This compares population-level mortality risk, not individual clinical outcomes. Acute vs chronic exposure differs significantly.
AQLI methodology: each 10 µg/m³ PM2.5 above WHO baseline (5.0 µg/m³) ≈ 0.98 years of life expectancy lost. Calculated from annual mean PM2.5 (long-term exposure), not annual median.
24-hour pattern from the most recent 7 days of hourly data. Dimmed arcs are unsafe for the selected activity.
This is a short-term trend view (not live minute-by-minute monitoring).
How does the air here compare to other health risks — and to peer cities?
Every day of the year, colored by PM2.5 air quality band.
The baseline view is No mask. You can switch to Surgical, KN95, or N95 to see a planning range for mask-adjusted exposure. Smoking-aware mode is optional and off by default.
Data-backed city context for Kathmandu, with practical interpretation.
Himalayan bowl traps cold air, vehicle fumes, waste burning and brick kiln emissions under inversion layer
Affects: Nov, Dec, Jan, Feb
Forest fires and agricultural burning on valley slopes before monsoon
Affects: Mar, Apr
Himalayan monsoon clears the valley air
Affects: Jul, Aug, Sep
Kathmandu residents lose an estimated 4.1 years of life expectancy on average due to PM2.5 air pollution — compared to living in a city that meets WHO air quality guidelines.
Each bar shows estimated life-years lost due to that risk factor. The orange bar is Kathmandu. Gray bars are risk comparisons.
Source: AQLI methodology — each 10 µg/m³ above the WHO 5 µg/m³ baseline ≈ 0.98 life-years lost. Population-level statistical estimates, not individual predictions. Methodology →
Tip: tap a day cell to pin details, tap outside to close.
All-years view shows the median across available years per calendar day. Individual year views show actual measured values. Methodology →
Smoking-aware mode is optional. Turn it on only if you want combined smoking + air burden estimates.
Berkeley Earth conversion: 22 µg/m³ PM2.5 ≈ 1 cigarette/day. Statistical communication tool — not a clinical diagnosis.
Planning estimate from monthly median PM2.5 values. Air-equivalent burden is additive and does not replace smoking burden.
Based on monthly median PM2.5 values. Actual exposure varies by fit, wear time, location, activity, and daily conditions. Methodology →
Kathmandu sits in a bowl ringed by the Himalayan foothills, and that geography is its pollution destiny. In winter, cold air drains down from surrounding slopes and pools in the valley under temperature inversions. Every source of combustion—vehicles, waste burning, cooking fires, brick kilns—has nowhere to go. January median: 90 µg/m³. No day in January or February in our dataset recorded better than Unhealthy air quality.
The annual median of 40.6 µg/m³ (4.13 years of life expectancy lost) is driven almost entirely by the winter inversion season (November–February). December is particularly severe: 79 µg/m³ median with hazardous days in every year of our dataset. Spring (March–April) adds pre-monsoon dust and fires on valley slopes before the rains arrive.
The monsoon (July–September) transforms Kathmandu. July and August both average around 18 µg/m³—the only period approaching WHO Moderate levels. Jogging and cycling are safe on virtually every day. August is the best month at 17.7 µg/m³.
October begins the deterioration at 40 µg/m³ as the post-monsoon transition starts. November rapidly worsens. The popular trekking season (October–November) coincides with significantly elevated pollution in the valley; those spending time in Kathmandu city should be aware, though high-altitude trails above the valley inversion layer will have considerably cleaner air.
Data: OpenAQ API v3 · WHO 2021 AQI Guidelines · Berkeley Earth · Methodology →