Report · 27 September 2026

85 AQI at Mundka, 24 hours to 4 PM, 27 September 2026, set by nitrogen dioxide. 18.3 lakh people live within 4 km of it.

103

TODAY, WEATHER REMOVED

This is Delhi in the usual weather for the season, on the model's 40 stations, which measured 58.

12.1 lakh

NEAR MODERATE OR WORSE

Within 4 km of 1 Moderate-or-worse monitors: 5.7 per cent of Delhi, every pollutant counted.

0.7x

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, 27 September 2026, 24 hours to 4 PM: the observed number looks better than last year, but the weather flag is up: with the weather removed, today is 0.8 points worse, on the model's count. The improvement is the weather's, not the Government's. Delhi's AQI was 57.6, Satisfactory, calculated with CPCB's documented formula as the mean of 40 stations' AQIs (CPCB's note "How is AQI calculated?" and its AQI Calculator; page 33 sets out the formula). The highest reading anywhere in Delhi today was 108 at Rohini, 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 (Rohini and Jahangirpuri), or on Pusa, whose nitrogen oxide readings fail this record's consistency check; the count below includes every pollutant. The highest reading that particle pollution set was 66 at Wazirpur, on PM10. 1 of 40 monitors read Moderate or worse on CPCB's documented formula, and 12.1 lakh people, 5.7 per cent of Delhi, live within 4 km of one.

The year so far, 1 January to 27 September: the cleaner days of 2026 have been the dirtiest for these dates since 2019, because three days in four read above 106.3 on the particle AQI, against 89.6 on the same dates of 2025.

The findings

What the report says

The verdict, both rulers

On the weather model's own count of 33 matched stations, the observed year reads -61.7 points; with the weather removed it reads +0.8 on the model's count; the stations are too mixed to call. 2 of 3 pollutants, PM2.5, PM10, show no real improvement.

Against yesterday: the one-day move

From 73 to 57. On the 39 stations that reported on both days, the 95 per cent interval runs -22.2 to -11 points.

Against last year: the observed reading

Today 58 across 40 stations. The year is judged on the 33 matched stations: 57 today against 122, the mean of the same date ±7 days of 2025 at those stations. The interval runs -73.4 to -57 points.

The highest reading this record leads on today

Satisfactory, set by nitrogen dioxide. Last year this station read 136 on the mean of the same date ±7 days, so the change is -51.3 points. 18.3 lakh people live within 4 km of this monitor. The highest reading of the day was 108 at Rohini, set by carbon monoxide. Within 500 m of the monitor, 73% of the land is built up and 24% is under vegetation, so this reading describes a densely built neighbourhood.

The year, from its best days to its worst

On the same 270 complete dates, 1 January to 27 September, the best tenth of days reads 74.7 against 71.9 and the worst tenth 291.8 against 296.6. The days at or below 200 went from 194 to 192.

How much of the city was above AQI 200

That is 11.5 of 43.2 reporting stations, against 26.4 per cent over the same dates last year, a change of +1.4 points on an interval of -3.9 to +6.5, 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 40 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 5.7 per cent of Delhi, living around the 1 monitor that read Moderate or worse. No monitor read Poor or worse today. The highest reading this record leads on is Mundka (DPCC) at 85, and 18.3 lakh people live within 4 km of it; the higher readings it sets aside are named below.

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