Report · 12 September 2026

99 AQI at Punjabi Bagh, 24 hours to 4 PM, 12 September 2026, set by PM10. 15.7 lakh people live within 4 km of it.

TODAY

Delhi's AQI calculated with CPCB's documented formula, the mean of 41 stations.

41.3 lakh

NEAR MODERATE OR WORSE

Within 4 km of 4 Moderate-or-worse monitors: 19.7 per cent of Delhi, every pollutant counted.

1.7x

THE WHO 24-HOUR LINE

Delhi's PM2.5 today, as measured, against the WHO 24-hour guideline.

The AQI figures here are calculated with the formula that the Central Pollution Control Board (CPCB) publishes for its air quality index. CPCB's own documents set out that formula: CPCB's note on how the AQI is calculated; CPCB's AQI calculator.

The full report

The complete written report for this day, with every figure and the source it comes from.

Download the daily reportPDF, 3.9 MB

The day in brief

Today, 12 September 2026, 24 hours to 4 PM: Delhi's AQI was 77, Satisfactory, calculated with CPCB's documented formula as the mean of 41 stations' AQIs (CPCB's note "How is AQI calculated?" and its AQI Calculator; page 32 sets out the formula). As measured, 36 of the 39 monitors reading PM2.5 were above the WHO 24-hour guideline of 15 µg/m³. The highest reading anywhere in Delhi today was 133 at NSIT Dwarka, and carbon monoxide set that figure. The figure at the head of this page is lower, because this record does not anchor its headline on a reading that carbon monoxide set (NSIT Dwarka and North Campus and Sonia Vihar); the count below includes every pollutant. 4 of 41 monitors read Moderate or worse on CPCB's documented formula, and 41.3 lakh people, 19.7 per cent of Delhi, live within 4 km of one.

The year so far, 1 January to 12 September: the cleaner days of 2026 have been the dirtiest for these dates since 2019, because three days in four read above 108.4 on the particle AQI, against 87.9 on the same dates of 2025. The middle day reads 154.0 against 143.5 on the same dates last year. On an average day, 29.2 per cent of Delhi's reporting monitors, about 12 of 43, sat above 200 on the particle AQI.

The findings

What the report says

Against yesterday: the one-day move

From 128 to 77. On the 41 stations that reported on both days, the 95 per cent interval runs -58.2 to -43.3 points.

Against last year: the observed reading

Today 77 across 41 stations. The year is judged on the 34 matched stations: 78 today against 101, the mean of the same date ±7 days of 2025 at those stations. The interval runs -31.6 to -13.8 points.

The highest reading not set by carbon monoxide

Satisfactory, set by PM10. Its PM10 averaged 101.6 µg/m³ over the 24 hours to 4 PM, 2.2 times the WHO 24-hour guideline of 45 µg/m³. Last year this station read 109 on the mean of the same date ±7 days, so the change is -9.5 points. 15.7 lakh people live within 4 km of this monitor. The highest reading of the day was 133 at NSIT Dwarka, set by carbon monoxide. Within 500 m of the monitor, 82% of the land is built up and 18% is under vegetation, so this reading describes a densely built neighbourhood.

The year, from its best days to its worst

On the same 255 complete dates, 1 January to 12 September, the best tenth of days reads 76.1 against 71.6 and the worst tenth 297.9 against 299.2. The days at or below 200 went from 179 to 177.

How much of the city was above AQI 200

That is 12.1 of 43.2 reporting stations, against 27.7 per cent over the same dates last year, a change of +1.5 points on an interval of -3.9 to +7.2, so it is unchanged inside its margin.

Who the monitoring network reaches

Within 4 km live 92 per cent of Delhi's people, within 2 km 45 per cent, and within 500 m only 3.6 per cent. Delhi has 55 monitors in 53 zones, of which 41 reported today, and 30 of the 53 zones stretch past 4 km, the distance that the US EPA's neighbourhood scale treats as the furthest a monitor speaks for.

What each monitor's reading speaks for

That is 19.7 per cent of Delhi, living around the 4 monitors that read Moderate or worse. No monitor read Poor or worse today. The highest reading this record leads on is Punjabi Bagh at 99, and 15.7 lakh people live within 4 km of it; the higher readings it sets aside are named below.

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