Ghaziabad was the most polluted city in India in October 2026, but no city averaged Poor

The most polluted city in India in October 2026 so far is Ghaziabad. From 1 to 24 October its government monitors recorded a mean daily India NAQI of 199, at the very top of the Moderate band, the highest of the 244 Indian cities we ranked. Ghaziabad's air was Poor or worse on 14 of the 24 days.

No Indian city averaged Poor (above 200) over the month so far. 118 cities averaged Moderate, 118 Satisfactory and 8 Good. Delhi came 18th, at 165. Six of the ten most polluted cities are in Uttar Pradesh, and several are small towns: Khora (197), Gajraula (191) and Baghpat (180) all had dirtier air than Delhi.

This is Good Air's own ranking from the Central Pollution Control Board (CPCB) monitor network. CPCB's daily bulletins give the same top city.

Key findings

• Ghaziabad was first, at 199. Its seven monitors put it in the Poor band on 14 days, more than any other city. PM2.5 averaged 89 µg/m³, about six times the World Health Organization's 24-hour guideline of 15 µg/m³.
• Delhi ranked 18th of 244, at 165, with 4 Poor days, all between 20 and 23 October.
• Two Madhya Pradesh towns made the top 10: Mandideep (177) and Pithampur (177), each with one monitor in an industrial area.
• The air got worse in the last week. On 10 and 12 October, CPCB's bulletin rated no city Poor. On 21 October it rated 25 cities Poor or worse.
• The cleanest air was in Madikeri (30) and Gangtok (30). Most of India's cleanest cities were in Karnataka and the north-east.

The 10 most polluted cities in India, October 2026

The table ranks cities by the mean of their daily India NAQI from 1 to 24 October 2026. "Days Poor or worse" counts the days on which a city's daily figure was above 200. India's NAQI runs from 0 to 500: 0 to 50 is Good, 51 to 100 Satisfactory, 101 to 200 Moderate, 201 to 300 Poor, 301 to 400 Very Poor and 401 to 500 Severe. The last column is the average of CPCB's own 4 pm bulletins over the same 24 days, as a check.

Ranks use unrounded means. Between Bhiwadi and Delhi came Muzaffarnagar (171), Bulandshahr (169), Gurugram (168), Yamuna Nagar (167), Meerut (166), Hingoli in Maharashtra (166) and Bhavnagar in Gujarat (166).

Ghaziabad also topped the last full winter. The Centre for Research on Energy and Clean Air (CREA) ranked it India's most polluted city from October 2025 to February 2026, with mean PM2.5 of 172 µg/m³, ahead of Noida and Delhi (The Wire, 8 March 2026).

Where Delhi ranks

Delhi was 18th, at 165. Thirteen of the 17 cities above it are in Uttar Pradesh, Haryana or Rajasthan, most within about 100 km of the capital. Delhi's daily figure stayed Moderate until 20 October, then was Poor for four days running: 230, 249, 243 and 202.

On 21 October CPCB's bulletin put Delhi at 245, and the Commission for Air Quality Management (CAQM) invoked Stage I of the Graded Response Action Plan (GRAP), Delhi NCR's emergency plan, across the whole region (PIB, 21 October). Our GRAP Stage 1 report explains what changed. For the street-by-street picture, our ranking of the most polluted areas of Delhi covers 68 monitors.

Small towns near the top

Several of the worst places are small towns:

• Gajraula had its worst days at the end of our period: 293 on 23 October and 301, Very Poor, on 24 October. CPCB's bulletin of 24 October rated it 309, also Very Poor (CPCB, 24 October).
• Khora reached 315, Very Poor, on 21 October, the day CPCB's bulletin gave it 317 (CPCB, 21 October).
• Mandideep and Pithampur each have one monitor, and CPCB's station names place both in industrial areas. CPCB listed PM10, the coarser particles that include dust, as the main pollutant on 17 of Mandideep's 23 bulletin days and 16 of Pithampur's 24.
• Bikaner in Rajasthan ranked 25th, at 153, but its PM2.5 was only 38 µg/m³, the lowest in our top 30. CPCB named PM10 as Bikaner's main pollutant in all 24 bulletins. Its AQI is high because of coarse particles, not smoke-sized ones. Sri Ganganagar, also in Rajasthan, was 22nd at 158.

Further from Delhi, the highest-ranked were Hingoli in Maharashtra and Bhavnagar in Gujarat (both 166), Talcher in Odisha (163), Agartala in Tripura (152) and Gummidipoondi in Tamil Nadu (150).

State by state

Uttar Pradesh had the dirtiest air as a state. Its median city averaged 130, and 11 of its 26 ranked cities averaged above 150. The table shows each state's median city, for states with at least five ranked cities. Delhi is a single city in our data.

The big southern and eastern metros were far cleaner than Delhi. Mumbai averaged 99 (119th), Kolkata 95 (130th), Hyderabad 74, Bengaluru 73 and Chennai 67, with no Poor days. Ahmedabad was the dirtiest of the large metros outside the north, at 133 (41st).

The cleanest cities in India

Eight cities averaged Good (50 or below). The cleanest were Madikeri in Karnataka (30) and Gangtok in Sikkim (30), followed by Naharlagun in Arunachal Pradesh (43), Chamarajanagar (45), Kalaburagi (45), Puducherry (46), Thiruvananthapuram (46) and Chikkaballapur (49). Four of the eight are in Karnataka.

The air got worse in the last week

By our daily figures, only one or two cities were Poor on 10, 11, 12 and 16 October. From 20 October the count jumped: 22 cities on 20 October, 21 on 21 October and 25 on 22 October. CPCB's bulletins show the same turn. They rated no city Poor on 10 and 12 October (CPCB, 10 October; 12 October) and 25 cities Poor or worse on 21 October. Our earlier comparison of India's air before and after the monsoon covers how the season began. The India page ranks every city live, and the daily India report lists each day's worst.

How we measured

• Data. Hourly readings from the continuous monitors in CPCB's national network, run by CPCB and state pollution control boards, as carried in Good Air's CPCB feed (city level). No satellite estimates, model output or low-cost sensors.
• Index. Good Air works out an India NAQI for every hour from that hour's readings; a city's daily figure is the mean of those hourly values. We rank on daily means, never on an hourly peak.
• Valid days. A day counts only with at least 12 hourly readings. Days run midnight to midnight UTC (5:30 am to 5:30 am in India). A city is ranked only with at least 18 valid days of the 24 from 1 to 24 October: 244 of 292 cities qualified.
• Dropped or flagged. We dropped five Bihar and Madhya Pradesh cities whose daily PM2.5 moved by 3 µg/m³ or less across the whole period, a sign of a stuck instrument: Satna, Bettiah, Arrah, Buxar and Chhapra. 43 cities had too few valid days. Two would have ranked high: Baraut (187 over 17 valid days; CPCB's bulletin rated it 324, Very Poor, on 24 October) and Ballabgarh (195 over 15 days, against a bulletin average of 156, so we do not trust its figure). Yamuna Nagar only just qualified, with 18 days. No two cities reported identical daily values, so none share a monitor.
• Check against CPCB. We read CPCB's 4 pm bulletins for all 24 days, which give each city's "average of past 24 hours". Averaged over the period, their top 11 are our top 10 plus Baraut. No city averaged above 200 in the bulletins either. For the median city our figure was 2% higher than the bulletin average, because our hourly method weighs smoggy nights a little more.
• States come from CPCB's labels and each monitor's operating board. A town with one monitor is described by one site.

We will rerun this ranking for the whole of October in early November.