Delhi Smog Atlas

The findings

The 10 causes of Delhi's air pollution, explained

This study combines published research with our own GIS analysis for 1–10 November 2026. For each cause you will find what it is, what research says, what the satellite, monitor and map data show, and the limits of the data.

Quick answer

The main causes of Delhi's air pollution, from the biggest to the smallest year-round impact:

  1. 01VehiclesAll year
  2. 02Secondary particles formed in the airMostly winter
  3. 03Road and construction dustPeaks in summer
  4. 04Industry and brick kilnsAll year
  5. 05Coal power plantsAll year
  6. 06Crop stubble burning (seasonal)Oct–Nov
  7. 07Household fuelWinter evenings
  8. 08Garbage burning and landfillsAll year
  9. 09Firecrackers (1–3 days)Diwali, weddings
  10. 10Weather and geography (makes everything worse)Oct–Feb

All 10 causes at a glance

Shares come from different studies with different methods, so they do not add up to 100%.
#CauseShare in researchWhat our data shows (Nov 2026)When it matters
1VehiclesAbout 28% of winter PM2.5; over half of Delhi's own (local) PM2.536,52Satellite NO₂ 1.71× higher over Delhi than countrysideAll year
2Secondary particlesAbout 32% of winter PM2.5, the largest part3057% of Delhi's PM2.5 level found 100–300 km awayMostly winter
3Road and construction dustAbout 17% of winter PM2.5; much more of PM10 in summer36Coarse dust ~76% of PM10 in May, ~37% in NovPeaks in summer
4Industry and brick kilns22–30% of PM2.5; kilns 8–14% across the Indo-Gangetic Plain34,463,014 kilns within 100 km; NO₂ follows industryAll year
5Coal power plantsFGD-exempt plants give 81% of power-plant SO₂ within 300 km72NO₂ plumes over 16 of 18 plantsAll year
6Stubble burningAverage 4.9% in 2025, 15.5% in 2024 (15 Oct–30 Nov)55Punjab fires down from 57,799 (2020) to 3,291 (2026); 2,180 fires in Delhi's air path on DiwaliOct–Nov
7Household fuelPart of biomass burning, about 24% of winter PM2.530~1 crore people nearby without clean cooking fuelWinter evenings
8Garbage and landfillsPM2.5 up 20–60% nearby during the 2022 Ghazipur fire6524 lakh people within 2 km of a landfillAll year, spikes during fires
9FirecrackersShort, sharp spikes; Diwali 2026 AQI 37653Diwali night PM2.5 above ordinary nights at 56 of 63 monitorsDiwali, weddings
10WeatherMultiplierVentilation 1,137–7,124 m²/s; 9 of 10 days poorOct–Feb