India's air-pollution challenge is real, but dramatic headlines often combine unrelated numbers: a winter peak at one Delhi monitor, a national annual average, an Indian Air Quality Index category, and a U.S. AQI conversion. Those values answer different questions.
This guide uses official Indian government data, the Central Pollution Control Board's index documentation, and World Health Organization guidance. It distinguishes annual PM2.5 concentration from daily AQI and explains why an Indian AQI cannot be entered into a U.S. AQI-to-cigarettes calculator.
The Latest Official Annual Snapshot
In a July 2026 parliamentary reply, India's Ministry of Environment, Forest and Climate Change reported the following FY 2025–26 annual PM2.5 concentrations for five National Clean Air Programme cities. The figures were published by the government's Press Information Bureau.
| City | FY 2025–26 annual PM2.5 (µg/m³) | Compared with India's annual standard | |---|---:|---| | Surat | 32 | Meets 40 µg/m³ standard | | Mumbai | 33 | Meets 40 µg/m³ standard | | Hyderabad | 34 | Meets 40 µg/m³ standard | | Pune | 41 | Above 40 µg/m³ standard | | Delhi | 102 | Above 40 µg/m³ standard |
The same official reply says 65 of the 130 cities covered by the programme met India's 40 µg/m³ annual PM2.5 standard in FY 2025–26. That is an important progress measure, but meeting a national legal standard is not the same as meeting the WHO health-based annual guideline of 5 µg/m³, published in the WHO Global Air Quality Guidelines.
The Delhi result also shows why a national average or a single “India AQI” label is inadequate. Annual concentrations differ markedly by city, and exposure can vary within each city by neighborhood, season, occupation, housing, and time spent near major sources.
Annual PM2.5 and Daily AQI Are Different Measures
Annual PM2.5 is a physical concentration averaged across a completed year, reported in µg/m³. It is useful for long-term trends, standards, and population exposure.
AQI is a communication index calculated from shorter-term pollutant measurements. The daily index tells people how current or recent air quality maps to health-advice categories. It is not a concentration unit, and its formula depends on the country.
A city can have a high annual PM2.5 burden while still recording some good days. It can also have a lower annual average but experience severe short episodes caused by smoke, dust, stagnant winter air, or other events. Neither measure should be substituted for the other.
How India's National AQI Works
The Central Pollution Control Board (CPCB) defines pollutant sub-indices for eight pollutants: PM10, PM2.5, nitrogen dioxide, sulfur dioxide, carbon monoxide, ozone, ammonia, and lead. The worst available pollutant sub-index determines the overall AQI, subject to CPCB's data-availability rules. The method and categories are documented in CPCB's National Air Quality Index report.
For a 24-hour PM2.5 concentration, the Indian breakpoints are:
| Indian category | Indian AQI | 24-hour PM2.5 concentration (µg/m³) | |---|---:|---:| | Good | 0–50 | 0–30 | | Satisfactory | 51–100 | 31–60 | | Moderate | 101–200 | 61–90 | | Poor | 201–300 | 91–120 | | Very Poor | 301–400 | 121–250 | | Severe | 401–500 | Above 250 |
This system is internally consistent for India. The problem begins when an app labels a number only as “AQI” and a reader assumes it uses U.S. breakpoints.
Indian AQI Is Not U.S. AQI
The U.S. Environmental Protection Agency uses different pollutants, category names, averaging conventions, and concentration breakpoints. For PM2.5 after the 2024 U.S. update, a 24-hour concentration of 35.5–55.4 µg/m³ maps to AQI 101–150, “Unhealthy for Sensitive Groups.” Under India's system, concentrations from 31–60 µg/m³ map to AQI 51–100, “Satisfactory.” The current U.S. table is published in EPA's official AQI breakpoint code table.
That does not mean one country is “calculating the air incorrectly.” An AQI is a policy communication framework. The same concentration can produce a different index number because the frameworks use different breakpoints.
There is a second issue: the overall Indian AQI may be driven by PM10, ozone, nitrogen dioxide, or another pollutant rather than PM2.5. Even if the displayed number happened to resemble a U.S. AQI, it would not identify a PM2.5 concentration without the pollutant-specific sub-index.
Practical rule: Before using any calculator, record the pollutant, concentration or index, averaging period, index country, timestamp, and station. If those fields are missing, do not convert the number.
Where the Pollution Comes From
There is no single percentage that accurately describes sources for every Indian city and season. India's 2026 parliamentary reply identifies multiple anthropogenic contributors: vehicle and industrial emissions, construction and demolition dust, road and open-area dust, biomass and municipal-waste burning, landfill fires, and other dispersed sources. Meteorology can compound those emissions.
The mix changes by place and time:
- In northern winter, shallow atmospheric mixing and regional transport can allow pollutants to accumulate.
- Road and construction dust contribute substantially to coarse particles in many cities.
- Fuel combustion produces primary particles and gases that form secondary PM2.5 in the atmosphere.
- Agricultural and biomass burning can influence downwind regions during episodic periods.
- Household cooking and heating fuels can add both indoor and outdoor exposure where clean alternatives are not available.
Source-attribution percentages should therefore cite a city-specific study, inventory year, pollutant, and model. A Delhi source-apportionment result cannot automatically be applied to Mumbai, and a winter result cannot be presented as an annual national share.
What the National Clean Air Programme Measures
India launched the National Clean Air Programme (NCAP) in 2019. The government states that the programme covers 130 cities and uses national, state, and city action plans. For FY 2025–26, 108 cities recorded lower annual PM10 than the 2017–18 baseline; 72 reduced PM10 by more than 20%, 26 by more than 40%, and 14 met the 60 µg/m³ PM10 standard, according to the same 2026 parliamentary reply.
Those numbers should be read carefully:
- The primary trend metric reported there is annual PM10, not PM2.5.
- A reduction from baseline does not necessarily mean the health-based WHO guideline has been reached.
- Weather and monitor coverage affect annual observations.
- Citywide progress can coexist with high-exposure neighborhoods.
The appropriate evaluation is not “NCAP solved pollution” or “nothing improved.” Official data show measurable progress in many participating cities and large remaining gaps in others, especially Delhi's reported FY 2025–26 PM2.5 concentration of 102 µg/m³.
Health Context Without Unsupported Predictions
Long-term PM2.5 exposure is associated with increased mortality from cardiovascular disease, respiratory disease, and lung cancer. WHO's guideline process evaluates the evidence across many cohorts and recommends lower concentrations to reduce population risk. An annual city value cannot predict how many years a particular resident will lose, and a single AQI reading cannot diagnose damage.
Children, older adults, pregnant people, and people with heart or lung conditions may need more cautious activity plans during polluted periods. Use current CPCB or local-authority guidance and a clinician's advice for personal medical decisions.
What Residents and Travelers Can Do With the Data
- Use CPCB or the responsible state board for current conditions. Confirm the station and dominant pollutant rather than relying on a screenshot from an unnamed app.
- Separate daily decisions from long-term choices. Today's AQI helps with outdoor activity; completed annual PM2.5 helps assess the background burden.
- Reduce indoor particle sources. Smoking, incense, candles, unvented combustion, and high-emission cooking can raise indoor PM2.5 even when outdoor air improves.
- Use correctly sized particle filtration when needed. Filtration can reduce particles but does not remove all gases and cannot make every environment risk-free.
- Follow pollutant-specific advice. A particle respirator can reduce inhaled particles when it fits correctly, but it does not protect against ozone or carbon monoxide.
Can Indian AQI Be Converted to Cigarette Equivalents?
Not directly. This site's estimate is built for a U.S. PM2.5 AQI. It first uses U.S. EPA breakpoints to estimate a 24-hour PM2.5 concentration and then applies a population-level risk-communication heuristic. An Indian overall AQI uses different breakpoints and may be driven by a different pollutant.
If an Indian monitoring source provides a validated PM2.5 concentration in µg/m³, use a tool designed for direct PM2.5 input and preserve the averaging period. Do not relabel an Indian AQI as U.S. AQI. Read the methodology before interpreting the output, which is not a measure of literal smoke inhalation or an individual medical forecast.
Bottom Line
India does not have one air-quality number. The latest official FY 2025–26 figures cited here range from 32 µg/m³ annual PM2.5 in Surat to 102 µg/m³ in Delhi. CPCB's Indian AQI is a valid national communication system, but it is not interchangeable with U.S. AQI. Responsible interpretation keeps the pollutant, unit, averaging period, city, station, year, and index system attached to every number.