Delhi Smog Atlas

Interactive map of the 10 causes of Delhi's air pollution

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Overview

One week, ten causes, one map

Scroll down. The map changes with each card. Tap any dot, line or coloured area to see its details. Use the search button on the map to see what is near your area.1,4,9

71%of 420 air-path runs came from the north-west, 24 h before reaching Delhi
9 of 10days had a ventilation index below 6,000 m²/s (poor dispersion)
63ground monitors with hourly data
3.9 kmsatellite NO₂ and SO₂ detail (Sentinel-5P)

Lines show where Delhi's air came from in the previous 48 hours, at three heights. Orange glow shows fire density. Shading shows hills such as the Aravallis.

Cause 1

Vehicles

Satellite NO₂ is 1.7 times higher over Delhi than over the countryside around it. Ground monitors show NO₂ rising in the morning and evening rush.1,3,9

1.71×NO₂ over central Delhi vs 80–150 km away (Sentinel-5P)
4.3×more NO₂ in rush hours than mid-day (model)
Read the full analysis
Cause 2

Secondary particles

Gases like NOx, SO₂ and ammonia react in the air and form tiny particles. The haze covers the whole Indo-Gangetic Plain, not only Delhi.1,9,30

57%of Delhi's PM2.5 level found 100–300 km away (model)
32%of winter PM2.5 in a real-time study, the largest part
Read the full analysis
Cause 3

Road and construction dust

Dust is mostly a summer problem. In April and May, coarse dust made up about three-quarters of PM10 over Delhi.1,9

~76%coarse share of PM10 in May (model)
~37%coarse share in November (model)
Read the full analysis
Cause 4

Industry and brick kilns

Satellite NO₂ follows industrial areas more closely than roads at the 1:30 pm satellite pass. 3,014 brick kilns sit within 100 km of Delhi.1,3,11,13

ρ 0.35industry vs satellite NO₂, with roads held constant
3,014brick kilns within 100 km
Read the full analysis
Cause 5

Coal power plants

Sentinel-5P shows NO₂ plumes over 16 of 18 coal plants. The two Jhajjar plants, 83–85 km west of Delhi, have 106–129% more NO₂ than their surroundings.1,3

+129%NO₂ over Indira Gandhi STPP, Jhajjar
+48%NO₂ over NTPC Dadri, 39 km east
Read the full analysis
Cause 6

Crop stubble burning

Satellite fire counts in India's Punjab fell from 57,799 (2020) to 3,291 (2026) for 1 Oct – 10 Nov. Pakistan's Punjab had 7,420; since 2024 it has had more fires than India's Punjab. 71% of Delhi's air paths came from the north-west.1,4

Read the full analysis
Cause 7

Household fuel

Delhi itself cooks almost fully with clean fuel. The problem is the ring of districts around it.1,6,15

~1 crorepeople in districts within 100 km live in homes without clean cooking fuel
22%clean fuel use in Nuh (Mewat), the lowest nearby
Read the full analysis
Cause 8

Garbage burning and landfills

About 24 lakh people live within 2 km of a mapped landfill or dump site. The Jahangirpuri monitor is about 1.6 km from the Bhalswa landfill.1,11,15

24 lakhpeople within 2 km of a landfill or dump
7.1%of the study area's population
Read the full analysis
Cause 9

Firecrackers

On Diwali night, PM2.5 was higher than on ordinary nights earlier that week (4–6 Nov) at 56 of 63 monitors. The biggest rise was at Sector-1, Noida (+407%).1,10

Read the full analysis
Cause 10

Weather and geography

Weather does not create pollution. It traps it. Diwali had the worst ventilation of the period: 1,137 m²/s.1,9

Read the full analysis
Exposure

Who breathes it

3.33 crore people live in the study area. People live where NO₂ is higher: population-weighted NO₂ is 13% above the area average.1,3,15

34%live within 500 m of a major road
33%live within 1 km of an industrial area
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Replay

Watch 1–10 November, hour by hour

Press play. Monitors change colour with PM2.5. Fires and air paths appear for each day.1,4,10

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Data