National air quality monitoring programme (NAMP) and CPCB data
CPCB's National Air Quality Monitoring Programme tracks SO2, NO2 and PM10, with PM2.5 at many stations. How sampling works and where to get yearly data.
National air quality monitoring programme (NAMP) in India
The National Air Quality Monitoring Programme (NAMP) is the Central Pollution Control Board's (CPCB) nationwide network for measuring ambient air quality in India. It tracks status and trends. It also checks where ambient standards are exceeded and helps identify non-attainment cities, according to CPCB's About NAMP page.
Its manual stations measure sulphur dioxide (SO2), nitrogen dioxide (NO2) and PM10 on a fixed schedule, and many also measure PM2.5. They don't give a live reading. For year-wise results, use CPCB's Ambient Air Quality Data page. For real-time readings and the AQI, use the separate CPCB Air Quality Portal.
Who runs the programme
NAMP also supports preventive and corrective action and studies how the atmosphere cleans itself. CPCB coordinates the programme. State Pollution Control Boards, Pollution Control Committees and other participating institutions carry out monitoring at the stations (CPCB).
You'll see two names on CPCB's own pages. The About page says "National Air Quality Monitoring Programme". The data page says "National Ambient Air Quality Monitoring Programme (NAMP)" (CPCB). Both refer to the same programme.
What NAMP measures
The core pollutants are SO2, oxides of nitrogen as NO2 and respirable suspended particulate matter (RSPM, or PM10). CPCB's monitoring network page says these three are monitored regularly at all locations.
PM2.5 is the fourth pollutant, but coverage is partial. On 19 November 2024, the network had 966 operating stations in 419 cities and towns, across 28 states and seven Union Territories. PM2.5 was measured at 611 of those stations, in 277 cities (CPCB).
CPCB's About page says all four pollutants, PM2.5 included, are monitored at all locations (CPCB). Both pages carry the same update date, 31 December 2024, but the network page gives explicit coverage counts. Check the annual file for the year you need before assuming a station has PM2.5 data.
Keep CPCB's wording, "oxides of nitrogen as NO2", when describing that parameter. Don't relabel the values as total NOx. Monitoring is accompanied by measurements of wind speed, wind direction, relative humidity and temperature (CPCB).
How manual sampling works
A manual air quality monitoring station doesn't run around the clock. The NAMP schedule is 24-hour monitoring twice a week, which targets 104 observations a year (CPCB). Within each monitoring day, that page describes these intervals:
- SO2 and NO2 use four-hourly sampling
- particulate matter uses eight-hourly sampling
- PM2.5 is specified separately as 24-hourly
The 104 figure is a target. It doesn't guarantee that every station delivered 104 valid results in a given year, so check the number of monitoring days where a table reports it.
CAAQMS full form and comparison with manual stations
CAAQMS stands for Continuous Ambient Air Quality Monitoring Station (CPCB technical guidelines). CPCB documents also use "system" in place of "station". The guidelines index, updated 6 April 2026, lists the "Technical Specifications for Continuous Ambient Air Quality Monitoring (CAAQM) Station (Real Time)" and a technical handbook for the continuous system. It also lists a protocol for agencies that run CAAQMS stations to send their data for AQI display. What differs is the schedule, and where you read the numbers (CPCB About NAMP, CPCB Air Quality Portal):
| Manual NAMP stations | CAAQMS | |
|---|---|---|
| How it measures | Scheduled sampling, 24 hours twice a week | Continuous, real-time monitoring |
| Where to see data | Year-wise tables on the Ambient Air Quality Data page | CPCB Air Quality Portal (CAQMS data, CAAQMS repository, AQI) |
If you need the AQI or the latest readings for a city, the manual tables won't help. The Air Quality Portal has separate sections labelled "All India CAQMS Data", "CAAQMS Data Repository" and "Air Quality Index".
Where to find NAMP annual data
CPCB air quality data from this manual programme is published year by year, not as a live feed. To get there from the CPCB site, go to Air | Water | Noise Data, then Air Quality Data, then Ambient Air Quality Data. The page has a selector headed "National Ambient Air Quality Monitoring Programme (NAMP) Data - Year wise". It lists 2024 back to 2013 (CPCB, updated 10 September 2026).
There is a second year-wise index at cpcb.gov.in/namp-data. It was updated on 23 June 2026 and lists 2023 back to 2013, plus a combined 2011-2015 report. It doesn't show 2024. The two pages simply aren't in sync, so start from the Ambient Air Quality Data page if you want the latest year.
Bookmark the landing page rather than a direct file address, and note the year and the date you downloaded the file.
How to read the results
Before you compare any two numbers, check four things in the table you've opened:
- Is it station-level or city-level? Don't assume every year uses the same structure.
- Which pollutant and which unit does each column use?
- What averaging period applies: a 24-hour value or an annual average?
- How many monitoring days lie behind the figure?
Then compare like with like. Check the file's notes for the meaning of blank cells or missing-value symbols. Don't treat them as zero.
CPCB adds its own warning. It says the data should be treated as "indicative rather than absolute", because results vary with the agency, staff, equipment, sampling, analysis and reporting (CPCB). Keep that in mind when you rank cities or read small changes from one year to the next.
Two more limits matter if you cite these figures in an assessment. An annual NAMP average isn't an AQI reading, and CPCB keeps the two in separate places (manual data, AQI portal). An ambient station average alone cannot establish a factory's permit compliance or a person's exposure. Use it within the programme's ambient-monitoring scope (CPCB, CPCB network page). For an environmental assessment, NAMP data is background context, so cite the station, year and file you used.
Consult newer reports before reusing the November 2024 station count as a description of today's network. CPCB's annual report index lists the Annual Report 2024-25, released 8 April 2026.
RegAffairs AI's NAMP answer offers a cited overview, but check pollutant coverage against CPCB's network breakdown.