Air quality in Delhi
How bad is the air in Delhi?
Delhi’s 2025 average of AQI 200 is Moderate on the CPCB scale, and the median day was 180. 285 days crossed 100 (Moderate or worse) and 164 crossed 200 (Poor or worse). 8 days were Severe, above 400.
The peak was AQI 461 on 14 December 2025. Fine particulate matter (PM2.5) set the index on 60% of days.
When Delhi’s air is worst
November is the worst month at a mean of AQI 354; July the cleanest at ~78. That is the post-monsoon pattern: cooler nights lower the mixing height, winds drop, and whatever the city emits stays over it.
Plan around the profile, not the average: a purifier sized for November covers the rest of the year with headroom, and windows can be opened in July.
Pollution in Delhi: what drives it
The main sources of air pollution in Delhi, per its NCAP city action plan and CPCB source studies, are vehicle exhaust, construction and road dust, stubble-burning smoke in October–November, winter temperature inversion and biomass and waste burning. CPCB bulletins name fine particulate matter (PM2.5) as the prominent pollutant on 60% of 2025's days.
- vehicle exhaust
- construction and road dust
- stubble-burning smoke in October–November
- winter temperature inversion
- biomass and waste burning
How Delhi compares
Among the 62 cities we map, Delhi has the highest annual AQI, against a median of 94 across those cities.
See the full ranking on the India Air Quality Index by city.
Do you need an air purifier in Delhi?
Verdict
Yes — Delhi needs one for a good part of the year.
With 164 days at Poor or worse and an annual average of 200, a bedroom-sized HEPA purifier run at 5 air changes an hour is the difference between sleeping in "Poor" air and "Satisfactory" air. Size it from room volume, not the coverage figure on the box.
What actually works
- Size by volume, not the box. Coverage claims assume ~2 air changes an hour; a November night wants 5.
- Bedroom first. Eight closed-door hours a night is where a purifier makes its measurable difference.
- Watch the live number. On Good and Satisfactory days, ventilate; on Poor days, close up and run the unit at the speed that delivers its CADR.
06 · The other half
Water in Delhi
Groundwater near Delhi averages ~994 mg/L TDS on CGWB monitoring — high on the BIS scale. The same government-data report, for what you drink.
Air
AQI 200
Moderate
Water
994 mg/L
TDS · High
Delhi air — questions
What is the AQI in Delhi today?
Today's figure comes from CPCB's live station feed and is shown at the top of this page, updated hourly when the feed is reachable. For context, Delhi averaged AQI 200 across 2025 and peaked at 461 on 14 December 2025, so a single day's reading should be judged against that range.
How bad is air pollution in Delhi?
Delhi's 2025 average of AQI 200 sits in CPCB's "Moderate" band. 164 days were Poor, Very Poor or Severe, and 79 days were Good or Satisfactory, out of 364 bulletin days.
Which month has the worst air quality in Delhi?
November, with a monthly average of AQI 354 in 2025. July was the cleanest at ~78. The post-monsoon build-up, cooler nights and a lower mixing height trap pollution from October onwards.
Is the air in Delhi safe to breathe?
Not by CPCB's own scale: an annual AQI of 200 is "Moderate", which CPCB associates with breathing discomfort on prolonged exposure for people with lung or heart disease, children and older adults. The 24-hour PM2.5 standard (60 µg/m³) is roughly where AQI passes 100.
Do I need an air purifier in Delhi?
Yes — Delhi needs one for a good part of the year. With 164 days at Poor or worse and an annual average of 200, a bedroom-sized HEPA purifier run at 5 air changes an hour is the difference between sleeping in "Poor" air and "Satisfactory" air. Size it from room volume, not the coverage figure on the box.
Where does Delhi's air pollution come from?
The main sources of air pollution in Delhi, per its NCAP city action plan and CPCB source studies, are vehicle exhaust, construction and road dust, stubble-burning smoke in October–November, winter temperature inversion and biomass and waste burning. CPCB bulletins name fine particulate matter (PM2.5) as the prominent pollutant on 60% of 2025's days.
Where does this air quality data come from?
From the Central Pollution Control Board's daily AQI bulletin, published at 4 PM as a 24-hour average for each city with continuous monitoring stations. This page aggregates 364 bulletin days for Delhi in 2025, drawn from 39 stations. The live figure uses the same CPCB station network through the Government of India's open-data feed.
Air quality in other cities
Data sources
- CPCB Daily AQI Bulletin (4 PM, 24-hour average), 2025 — city-level National AQI, prominent pollutant and station counts
- CPCB National Air Quality Index (2014) — six-band scale used for all categories
- NAAQS 2009 (24-hour PM2.5 60 µg/m³, PM10 100 µg/m³) — the concentrations that mark the Satisfactory/Moderate boundary
- Live readings: CPCB real-time station feed via data.gov.in, refreshed hourly.
Primary dataset: Central Pollution Control Board (CPCB) National Air Quality Index, Government of India.
Disclaimer: Figures are city-level averages of the CPCB daily AQI bulletin for the year shown and may differ from the air at your address, which depends on traffic, construction and the nearest station. This page is general information, not medical advice; for respiratory or cardiac conditions consult a qualified professional. Any purifier guidance is general sizing advice, not a product recommendation.