Frequently Asked Questions
Practical answers about AQI, pollutants, household protection, and how this independent site uses public monitoring data. For full explainers, visit the Learn library.
What is the Air Quality Index (AQI)?
The Air Quality Index (AQI) is a public communication score that converts concentrations of major air pollutants into a single number and colour band people can act on. India’s National AQI is maintained under the Central Pollution Control Board framework and typically considers pollutants such as PM2.5, PM10, NO2, SO2, CO, and ozone. Instead of comparing raw micrograms per cubic metre under time pressure, you can read a band such as Good, Satisfactory, Moderate, Poor, Very Poor, or Severe and adjust outdoor plans, school activities, or indoor filtration accordingly. AQI is a risk communication tool, not a full laboratory report and not a medical diagnosis.
How is AQI calculated in India?
Each pollutant concentration is first converted into its own sub-index using official breakpoint tables. The overall AQI for a location is generally the highest of those valid sub-indices—the worst pollutant “wins” so a dangerous spike is never averaged away. For example, if PM2.5 maps to 260 and ozone maps to 110, the headline AQI is 260 (Poor). That is why dominant pollutant labels matter: winter mornings in north India are often PM2.5-led, while hot afternoons can be ozone-led. For a full plain-language walkthrough, read our guide on how India’s AQI is calculated.
What do different AQI levels mean for daily life?
In India’s commonly used bands: 0–50 (Good) supports normal outdoor routines and ventilation; 51–100 (Satisfactory) is acceptable for most people though sensitive individuals may notice mild irritation; 101–200 (Moderate) is when asthma, heart patients, children, and elders should start shortening outdoor exertion; 201–300 (Poor) means most people can feel effects with longer exposure; 301–400 (Very Poor) calls for strong indoor protection and limited outdoor time; 401–500 (Severe) is hazardous for the general population. Exact personal risk still depends on health status, duration outdoors, and whether PM2.5, dust, or gases are driving the index. Use the Health Guide playbook for band-by-band actions.
Why should I monitor AQI instead of only looking at the sky?
Haze is a clue, not a measurement. Harmful PM2.5 can be elevated before the sky looks dramatic, and some gaseous pollutants are not obvious visually. Monitoring helps you choose safer windows for school runs, two-wheeler commutes, outdoor sports, and home ventilation. It is especially useful for households with children, pregnancy, asthma, COPD, or heart disease, where acting at Moderate is wiser than waiting for Severe. Pair the number with timestamps and dominant pollutant so you are not making decisions on stale or misread data.
What are the main air pollutants on Indian dashboards?
You will most often see PM2.5 (fine combustion-related particles), PM10 (coarser dust from roads, soil, and construction), NO2 (traffic and combustion), SO2 (certain industrial and fuel sources), CO (incomplete combustion, including generators and vehicles), and ground-level ozone (formed in sunlight from precursor emissions). PM2.5 is frequently the winter driver across large parts of north India; PM10 often rises with dust storms and construction; ozone can peak on hot, sunny afternoons. Our PM2.5 vs PM10 guide explains how the difference changes protection choices.
How often is AQI data updated on Track India AQI?
We request public monitoring records from government-linked feeds and display the newest valid timestamps returned for each station and pollutant. Many stations aim for hourly-scale updates, but real-world cadence varies with station uptime, network delays, and maintenance. Always check the “last updated” time on cards and city pages. If timestamps are old, treat the view as degraded and recheck before long outdoor exposure. Cached responses on this site stay fresh for a short window so the interface remains usable without hammering public APIs.
What should I do when AQI is high?
Reduce dose: shorten outdoor time, move workouts indoors, close windows during peaks, run HEPA filtration in a designated clean room, and wear a well-fitted N95/N99 when you must go out. Avoid adding indoor smoke from frying, incense, or waste burning. Batch errands, prefer cleaner commute modes when possible, and check on elders or neighbours with heart or lung disease. If AQI stays Poor or worse for days—common in winter smog episodes—switch to a multi-day plan rather than improvising each morning. See the winter smog family plan and Health Guide for checklists.
Where does Track India AQI data come from?
Live readings are drawn from public air-quality records associated with India’s monitoring network and exposed through government data portal endpoints. We filter incomplete rows, normalise timestamps, and present station and pollutant breakdowns for usability. Track India AQI is an independent site, not an official CPCB service. For methodology details, limitations, and editorial rules for city guides, open the Methodology page. For policy or emergency orders, always prefer primary government notices.
Is the data accurate enough to trust for family decisions?
Public station data is the best widely available real-time signal for many Indian cities, but it is not perfect. Stations can go offline, neighbourhood air can differ a few kilometres away, and some pollutants may be missing from a given update. Use AQI as a planning aid: prefer recent timestamps, compare multiple stations when shown, and escalate earlier for sensitive family members. For medical decisions, talk to a clinician. For regulatory actions (school closures, vehicle restrictions), follow official bulletins.
How can I protect indoor air on bad days?
Create one clean room, seal obvious gaps during peaks, run a HEPA purifier sized for the room, control indoor sources (cooking smoke, incense, open burning), and use short, timed ventilation only when outdoor AQI improves. Wet mopping and leaving shoes at the door reduce resuspended dust. Filter replacements and pre-filter cleaning matter as much as the initial purchase. Our air purifier guide covers CADR, room sizing, noise, and running cost so you do not overbuy features that do not filter particles.
What is the difference between PM2.5 and PM10?
Both are particulate matter, distinguished by size. PM10 includes larger dust particles that mainly affect the upper airways; PM2.5 is finer, more often combustion-related, and can travel deeper into the lungs and bloodstream. On dusty construction corridors PM10 may lead the AQI; during winter smog PM2.5 often dominates. Protection overlaps (filtration, reducing outdoor dose) but emphasis shifts: dust events reward site controls and eye protection; smog events reward sealed filtration and high-quality respirators. Read the dedicated PM2.5 vs PM10 article for seasonal examples.
Can long-term exposure to poor air quality affect health?
Yes. Sustained exposure to elevated particulate pollution is linked in public health research to respiratory disease, cardiovascular strain, adverse birth outcomes, and reduced life expectancy. Children, older adults, pregnant people, and those with existing heart or lung disease carry higher risk. Reducing cumulative dose—cleaner commute choices, less household smoke, indoor filtration during peaks, and supporting cleaner local policy—matters more than any single day of perfect behaviour. This site offers education and data context; it does not replace personal medical care.
Why do some city pages say they are dashboard-only?
We refuse to mass-publish thin location pages that only swap a city name into generic text. Dashboard-only pages still let visitors check live stations, but they stay out of search indexing until we write original local context—pollution drivers, seasonal notes, and practical actions for that city. Published guides appear in the City Guides directory. That editorial standard exists specifically to avoid low-value doorway pages.
Who runs Track India AQI and how do I report a mistake?
The project is maintained independently by Sanjeev K. It is not a government body. Email corrections, broken charts, or content gaps to ksanjeev284@gmail.com with the page URL, city or station name, and a short description of what looks wrong. Clear, specific reports improve the site faster than generic feedback. Privacy and terms pages explain how contact email and standard technical logs are handled.
Still have questions?
If you could not find the answer, send a specific note with the page URL and city or station involved.
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