Perundurai — Seasonal Pollution Patterns
Month-by-month air quality patterns for Perundurai across 1 years of CPCB data. Based on CPCB station data, 2016–present.
Tamil Nadu · Live Perundurai AQI →
At a glance
Based on 1 years of CPCB monitoring across 1 stations, Perundurai averages AQI 75 annually, with a pronounced seasonal pattern classified as flat year-round. The worst month is November at AQI 83 (Satisfactory) and the cleanest is December at AQI 65 (Satisfactory) — a 18-point swing between them. Severe days (AQI > 400) make up 0% of the record while Good-or-Satisfactory days account for 80.7%.
The four seasons
Indian meteorological seasons: Winter (Dec–Feb), Summer (Mar–May), Monsoon (Jun–Sep), Post-monsoon (Oct–Nov).
Winter
AQI 65Summer
AQI 0Monsoon
AQI 0Post-monsoon
AQI 82Climograph — monthly averages and Poor+ days
Bars show the long-run AQI average per month. The overlay line counts days in Poor, Very Poor or Severe bands.
Year × month heatmap
One cell per year-month combination.
Each cell = monthly average AQI for that year-month combination. Row averages on the right, column averages at the bottom.
| Year | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Avg |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2024 | — | — | — | — | — | — | — | — | — | 67 | 83 | 65 | 75 |
| Avg | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 67 | 83 | 65 | — |
Winter in Perundurai
Winter (Dec–Jan–Feb) in Perundurai averages AQI 65 across 25 measured days — Satisfactory on the NAQI scale. 0% of those days fall in Very Poor or Severe; 92% are Good or Satisfactory. Winter in Perundurai is not the headline season, but shallow morning inversions can still produce short spikes. Perundurai's cleanest months lie elsewhere in the calendar, so the winter response is less about evacuation than about protecting sensitive groups on the worst individual days.
Diwali, stubble burning and the monsoon
Three India-specific signatures that shape the seasonal curve.
Stubble-burning window (Oct 15 – Nov 15)
In-window severe-day share 0% vs 0% outside the window. The difference is a direct signal of upwind crop-residue transport.
Summer
Summer (Mar–Apr–May) in Perundurai averages AQI 0 across 0 measured days — Good on the NAQI scale. 0% of those days fall in Very Poor or Severe; 0% are Good or Satisfactory. Summer air in Perundurai is shaped by a very different mix of forces. Rising temperatures drive deeper vertical mixing which dilutes local emissions, but pre-monsoon dust storms, wildfires and heat-accelerated ozone formation can all push AQI higher on individual days. Perundurai's summer mean of 0 is the lighter side of the year for outdoor activity, though hot afternoons can still irritate sensitive airways.
Monsoon
Monsoon (Jun–Jul–Aug–Sep) in Perundurai averages AQI 0 across 0 measured days — Good on the NAQI scale. 0% of those days fall in Very Poor or Severe; 0% are Good or Satisfactory. Rain scrubs particulates out by wet deposition, and the deeper monsoon boundary layer disperses what remains vertically. Short-lived rebounds can happen between spells of rain, but the overall pattern is strongly favourable for outdoor activity. For anyone with asthma or heart conditions, monsoon is the easy-breathing stretch of the year in Perundurai.
Post-monsoon
Post-monsoon (Oct–Nov) in Perundurai averages AQI 82 across 32 measured days — Satisfactory on the NAQI scale. 0% of those days fall in Very Poor or Severe; 71.9% are Good or Satisfactory. Post-monsoon in Perundurai is the handoff from clean monsoon air to the winter peak, and the transition is rarely gentle.
Month-by-month trajectories
How each month has moved across the 1-year CPCB record.
Daily calendar heatmap
Every measured day for the last 1 years. Expand for the full 1-year archive.
Month-by-month deep dive
Tap any month to expand.
Jan—+0%
No data for this month.
Feb—+0%
No data for this month.
Mar—+0%
No data for this month.
Apr—+0%
No data for this month.
May—+0%
No data for this month.
Jun—+0%
No data for this month.
Jul—+0%
No data for this month.
Aug—+0%
No data for this month.
Sep—+0%
No data for this month.
Oct2024–2024Latest AQI 67+0%
Oct in Perundurai averages AQI 67 (Satisfactory) in the most recent year, having moved from 67 in 2024. Direction: stable (+0.0%).
Nov2024–2024Latest AQI 83+0%
Nov in Perundurai averages AQI 83 (Satisfactory) in the most recent year, having moved from 83 in 2024. Direction: stable (+0.0%).
Dec2024–2024Latest AQI 65+0%
Dec in Perundurai averages AQI 65 (Satisfactory) in the most recent year, having moved from 65 in 2024. Direction: stable (+0.0%).
Cities with similar (and opposite) seasonal profiles
Ranked by cosine similarity of 12-month AQI signatures across monitored Indian cities.
What to do with this information
If you are choosing when to visit Perundurai or plan outdoor events — marathons, weddings, school sports, outdoor festivals — the CPCB record says December and the two adjacent months are the lowest-risk window. Daily variability still matters; check the live AQI page before committing on any specific date. Sensitive groups should treat November in Perundurai as an indoor-air-priority month: close windows on high-AQI evenings, run a purifier with a HEPA filter rated for your room size, and reserve outdoor exercise for clear-weather mornings. On days above AQI 300, even healthy adults benefit from well-fitted N95 or KN95 masks for outdoor commutes.
Frequently asked questions
Which is the most polluted month in Perundurai?
November is the most polluted month in Perundurai on average, with a long-run AQI of 83 — firmly in the Satisfactory band. This is drawn from 1 CPCB monitoring stations across 1 years of daily readings. Through November, residents should expect elevated PM2.5 and PM10, reduced visibility on cooler mornings, and strong recommendations from doctors to limit outdoor exertion, wear well-fitted N95 masks, and run indoor purifiers through evening and overnight hours when pollutant accumulation typically peaks.
What is the cleanest month to visit Perundurai?
December is the cleanest month of the year in Perundurai, averaging AQI 65 in the Satisfactory band. The months immediately before and after also tend to sit well below the annual mean of 75, so a visit window centred on December is the safest choice for outdoor sightseeing, marathons, school trips and wedding events. Mornings are usually the crispest time to head out; pollution tends to creep up slightly during the evening commute even in the cleanest months. Always cross-check the day-of live AQI before any high-exertion outdoor plan.
Why does Perundurai's air spike in November?
Perundurai's profile is relatively flat year-round; the small November reflects modest swings in wind, rainfall and local emissions rather than a dramatic seasonal mechanism.
How bad is Diwali air quality in Perundurai?
There is not yet enough CPCB data to quantify Diwali's impact specifically in Perundurai, but firework-driven spikes are well documented across north Indian cities in late October and early November.
Does the monsoon actually clean Perundurai's air?
Monsoon cleansing depends on local geography and emissions mix; we need more CPCB data to quantify the effect in Perundurai.
Is Perundurai's worst season getting worse or better year-on-year?
We need more years of CPCB coverage in Perundurai to quantify year-on-year change with confidence.
Which months are safest to visit Perundurai?
December is the single best month at AQI 65. Based on the 12-month averages, the three cleanest months in Perundurai are December (AQI 65), October (AQI 67), November (AQI 83). These are the safest choices for outdoor itineraries, long walks, open-air concerts and day-trips. Sensitive groups can treat these months as near-normal activity windows but should still check live AQI for the specific date. Avoid planning outdoor-heavy trips in November, when the baseline jumps into Satisfactory territory.
How does Perundurai's seasonal pattern compare to Delhi?
Perundurai is classified as flat year-round, while Delhi is strongly winter-dominant with a large Diwali and stubble-burning signal. If the two look similar, interventions that work in Delhi (BS-VI vehicle rollout, construction-dust control, seasonal industry curtailment) are worth trialling here. If they look very different, the dominant sources in Perundurai are likely different and the policy mix should reflect that.