What is the air quality in Kolkata? Live data, ranked.

Air quality in Kolkata is not one number. The official citywide AQI you see on the news averages readings from multiple monitoring stations, but within a city of 69 distinct residential localities the actual readings vary substantially from one neighbourhood to the next. This page ranks every Kolkata locality we cover by current AQI, sourced from the nearest CPCB-network station, updated hourly. Use it to compare addresses at a glance, to understand which pockets consistently show cleaner air, and to plan around the seasonal patterns that shape the city’s respiratory reality.

The leaderboard below is live. Readings come from the nearest active CPCB-network monitoring station to each locality, typically within 1 to 5 kilometres. When two adjacent localities share the same nearest station they will show the same reading, which is an honest limitation of station density rather than a flaw in the data. If you are new to AQI categories, 0 to 50 is Good, 51 to 100 is Satisfactory, 101 to 200 is Moderate, 201 to 300 is Poor, 301 to 400 is Very Poor, and above 400 is Severe.

Current air quality across Kolkata

Best air quality: the cleanest pockets in Kolkata

The cleanest areas in Kolkata are the ones you would expect if you understand the local geography. South Kolkata residential pockets with tree cover (Lake Gardens, Golf Green, Ballygunge, Tollygunge). These show up at the top of the leaderboard most days, though readings shuffle daily with weather.

A few caveats worth stating plainly. First, the rankings above reflect current readings not annual averages, so a locality can appear at the top on one day and midtable on another depending on wind direction, time of day, and the specific station feeding that locality. Second, station density is uneven across the city: some locality rankings reflect the genuinely local air while others reflect the nearest available station which may be a couple of kilometres away. Third, cleanest here is a relative statement within Kolkata. On the days when the city average sits at 143, even the top-ranked locality is probably still in the Moderate or Poor band by national standards.

Worst air quality: the most polluted pockets in Kolkata

The worst AQI readings in Kolkata cluster in predictable places. North Kolkata industrial corridors, parts of Howrah-adjacent belt, and areas along the Eastern Metropolitan Bypass during rush hour. If you are house-hunting in any of these zones, check the leaderboard more carefully and visit at different times of day before committing.

Buying or renting in one of these zones is not automatically a mistake. Price premiums in the cleanest pockets of Kolkata can be substantial, and for households without respiratory vulnerabilities the trade-off may make sense. What we would strongly recommend is that you understand what you are buying: visit the locality at 7 AM in winter before signing anything, ask about air purifier budgets as part of ongoing running cost planning, and look at apartment orientation (higher floors away from arterial roads typically read better than lower floors facing traffic).

How Kolkata’s air quality has changed year over year

Kolkata’s annual average AQI by calendar year: 2020 (94), 2021 (122), 2022 (116), 2023 (118), 2024 (118), 2025 (127). Annual averages have worsened measurably across the series, rising roughly 35% between 2020 and 2025. Early 2026 year-to-date is running around 143, though this will drop as the monsoon arrives and the full-year average typically lands closer to the historical range.

Kolkata sits on the Hooghly floodplain with flat terrain and minimal elevation change. There is almost no natural ventilation relief from hills or sea breeze once the monsoon withdraws, so winter stagnation traps pollutants close to ground level. The Bhagirathi-Hooghly basin funnels north-easterly winter winds that carry smoke from brick kilns in South Bengal and rice stubble burning pockets across the Indo-Gangetic plain.

The Graded Response Action Plan for Kolkata was first notified by the West Bengal Pollution Control Board in 2020 with response triggers at AQI 200, 300, and 400. Enforcement remains uneven and construction restrictions typical of Delhi-NCR have not been systematically applied in Kolkata.

Seasonal pattern through the year

Air quality in Kolkata follows a strong seasonal cycle. Understanding the shape of that cycle matters more than the annual average, because the difference between a clean month and a polluted month is typically larger than the difference between two neighbourhoods in the same month. If you are considering a long-term move to Kolkata, the honest stress-test is how you will feel about the worst six weeks of the year, not the best.

October to February (winter) is the worst stretch. As temperatures drop, a shallow inversion layer forms each night and traps PM2.5 from vehicles, cooking smoke, and long-range transported pollution from Punjab-Haryana stubble burning. Daily peak AQI readings in December and January routinely cross 250 at multiple stations, with Severe category (above 400) logged a handful of times each winter. Morning readings between 6 AM and 9 AM are typically the worst of the day. March to May (summer) sees improvement as daytime convection disperses pollutants vertically. Average AQI settles in the 90 to 140 range. Pre-monsoon dust events and the occasional kalbaisakhi thunderstorm can spike or crash readings on specific days. June to September (monsoon) is by far the cleanest. Persistent rainfall scavenges particulates from the atmosphere and south-westerly winds bring relatively clean maritime air. Daily averages commonly drop below 60, and stations like Rabindra Sarobar regularly log Good category readings (under 50) through July and August.

What the AQI bands actually mean for you

The Indian National AQI scale is structured around what different concentration levels mean for human health, especially for sensitive groups. Knowing where the current reading sits matters more than memorising the number.

• 0 to 50 (Good): Minimal health risk. Outdoor activity is safe for everyone including children, seniors, and people with respiratory conditions. Kolkata sees this band primarily during heavy monsoon days.
• 51 to 100 (Satisfactory): Acceptable for healthy adults. Sensitive individuals including asthmatics may notice mild irritation during prolonged outdoor exertion. This is the realistic best you will see in Kolkata during most of the year.
• 101 to 200 (Moderate): Unusual breathing discomfort possible for people with lung or heart disease. Healthy adults are largely unaffected for short outdoor trips but may notice minor irritation during sustained exertion. Much of the year in Kolkata falls in this band.
• 201 to 300 (Poor): Respiratory discomfort likely for people on prolonged exposure. Sensitive groups should limit outdoor activity and keep windows closed during peak hours. Air purifiers become genuinely useful in this band.
• 301 to 400 (Very Poor): Respiratory illness on prolonged exposure for everyone. All outdoor exertion should be avoided by sensitive groups. N95 masks are the practical response for time spent outdoors.
• 401 and above (Severe): Health impact on everyone, even healthy adults. Schools typically close, outdoor work halts, and respiratory hospital admissions rise measurably. Kolkata reaches this band primarily during peak winter episodes.

How this data works: methodology and limitations

Every number on this page comes from active CPCB-network monitoring stations, accessed via the WAQI API which aggregates data from CPCB and state pollution control boards. Kolkata currently has roughly 9 to 11 active stations including Victoria Memorial, Rabindra Bharati University, Rabindra Sarobar, Jadavpur, Ballygunge, Bidhan Nagar, Fort William. Each locality on HouseIQ is mapped to its geographically nearest station using haversine distance, and the current AQI value displayed reflects that station’s most recent reading.

Dominant pollutant in Kolkata is typically PM2.5, though the mix shifts seasonally. Readings are cached for one hour server-side to respect the upstream API’s rate limits and to keep page loads fast. If the WAQI feed is temporarily unreachable the widget falls back to the last known reading with a timestamp, so the page never shows broken data, but readings more than a few hours old should be treated as indicative rather than current.

Three limitations we want to flag honestly. First, a single monitoring station cannot fully represent a locality several kilometres across. Pollution varies at the street level, especially near construction sites, industrial units, or traffic corridors. Second, mapping by nearest station means two neighbouring localities sometimes share the same reading; this is correct given the data available but it does not mean the two localities always have identical air. Third, the AQI number is a composite across six pollutants (PM2.5, PM10, ozone, NO2, SO2, CO) and does not capture the specific mix of contaminants in your locality. For serious decisions about respiratory health, consult local air quality experts who can audit specific addresses.

Frequently asked questions

How often is the air quality data updated?

Station readings refresh every hour on HouseIQ, pulled from the WAQI network which itself sources from CPCB and state pollution control boards. The underlying CPCB stations typically report hourly averages, so anywhere you see a reading, it represents the average pollution level during the most recently completed hour, not a live second-by-second value.

Why do two neighbouring localities sometimes show the same AQI?

Kolkata has roughly 9 to 11 active monitoring stations spread across roughly 69 residential localities we cover. That means each station serves multiple surrounding localities. Two localities that both sit closest to the same station will show the same reading, which is an honest data limitation rather than a bug. If you are serious about comparing two specific addresses, check back at different times of day and across seasons to see where the real differences show up.

Which month is cleanest in Kolkata?

Based on the five-year pattern, the cleanest month is typically July or August with average AQI in the 40 to 80 range. The worst month is typically January or occasionally December, when average AQI can reach 180 to 280.

Should I buy an air purifier if I live in Kolkata?

If your locality’s AQI regularly crosses 150 during any part of the year, an air purifier for your bedroom at minimum is a reasonable investment. Look for models with HEPA filtration rated for room volume roughly 1.5 times the actual room size. For Kolkata, the winter months specifically are when purifiers earn their cost. HouseIQ does not sell purifiers and has no affiliate relationships; we recommend evaluating options through independent reviews rather than any one retailer.

Is the AQI on HouseIQ the same as what I see on other apps?

HouseIQ uses the Indian National AQI scale from CPCB. Some international apps like AirVisual or Plume Labs use the US EPA scale which calculates AQI slightly differently, so the same PM2.5 concentration might display as 120 on one app and 140 on another. The underlying air is the same; only the formula varies. We stick to the Indian National AQI because it is the scale Indian residents are most familiar with and what government bulletins reference.

Can I get historical trend data for a specific Kolkata locality?

HouseIQ is building a 30-day rolling history per monitoring station, accumulated daily. This data appears as a sparkline on each locality’s page once sufficient history has been collected. For longer historical trends, CPCB’s data portal at cpcb.nic.in and third-party archives like aqicn.org offer year-level statistics for major stations.

Does HouseIQ factor air quality into the livability score?

Yes. Air quality is one of the 12 factors in the HouseIQ composite score, weighted alongside schools, safety, commute, healthcare, and other dimensions. The livability score on each locality page reflects long-term air quality patterns for that area, not today’s reading. The live AQI widget on each locality page shows current conditions and is meant as a separate, real-time signal.