Bilaspur — Seasonal Pollution Patterns
Month-by-month air quality patterns for Bilaspur across 4 years of CPCB data. Based on CPCB station data, 2016–present.
Chhattisgarh · Live Bilaspur AQI →
At a glance
Based on 4 years of CPCB monitoring across 1 stations, Bilaspur averages AQI 69 annually, with a pronounced seasonal pattern classified as flat year-round. The worst month is December at AQI 89 (Satisfactory) and the cleanest is September at AQI 54 (Satisfactory) — a 35-point swing between them. Severe days (AQI > 400) make up 0% of the record while Good-or-Satisfactory days account for 88.0%.
The four seasons
Indian meteorological seasons: Winter (Dec–Feb), Summer (Mar–May), Monsoon (Jun–Sep), Post-monsoon (Oct–Nov).
Winter
AQI 79Summer
AQI 66Monsoon
AQI 59Post-monsoon
AQI 77Climograph — 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2021 | — | — | — | — | — | — | — | — | 57 | 81 | 79 | 95 | 83 |
| 2022 | 66 | 55 | 57 | 61 | 57 | 61 | 71 | 65 | 59 | 62 | 73 | 87 | 65 |
| 2023 | — | 74 | 93 | 88 | 84 | 79 | 91 | 58 | 54 | 99 | 69 | 109 | 81 |
| 2024 | 96 | 60 | 52 | 58 | 58 | 48 | 46 | 43 | 47 | 64 | 90 | 73 | 61 |
| Avg | 82 | 63 | 67 | 66 | 64 | 61 | 68 | 55 | 54 | 75 | 79 | 89 | — |
Winter in Bilaspur
Winter (Dec–Jan–Feb) in Bilaspur averages AQI 79 across 234 measured days — Satisfactory on the NAQI scale. 0% of those days fall in Very Poor or Severe; 79.1% are Good or Satisfactory. Year-on-year, winter improved by 12.6% in the most recent comparison. Winter in Bilaspur is not the headline season, but shallow morning inversions can still produce short spikes. Bilaspur'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.
Diwali week impact
The 7-day window around Diwali averages AQI 85 (Satisfactory), versus 75 (Satisfactory) for the rest of October. 27 sampled days across the CPCB record.
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.
Monsoon cleansing (Jul 15 – Sep 15)
Core monsoon window averages AQI 59 (Satisfactory), compared with an annual mean of 69.
Summer
Summer (Mar–Apr–May) in Bilaspur averages AQI 66 across 231 measured days — Satisfactory on the NAQI scale. 0% of those days fall in Very Poor or Severe; 90.5% are Good or Satisfactory. Year-on-year, summer improved by 37.2% in the most recent comparison. Summer air in Bilaspur 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. Bilaspur's summer mean of 66 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 Bilaspur averages AQI 59 across 319 measured days — Satisfactory on the NAQI scale. 0% of those days fall in Very Poor or Severe; 95.3% are Good or Satisfactory. Year-on-year, monsoon improved by 34.2% in the most recent comparison. The Jul 15 – Sep 15 core monsoon window averages AQI 59, a 14.5% improvement on the annual mean of 69. 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 Bilaspur.
Post-monsoon
Post-monsoon (Oct–Nov) in Bilaspur averages AQI 77 across 221 measured days — Satisfactory on the NAQI scale. 0% of those days fall in Very Poor or Severe; 84.2% are Good or Satisfactory. Year-on-year, post-monsoon improved by 11.4% in the most recent comparison. Post-monsoon in Bilaspur 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 4-year CPCB record.
First year vs latest year
Annual and per-season comparison.
Across the 4-year CPCB record Bilaspur is improving overall — AQI moved from 83 in 2021 to 61 in 2024, a -26.5% change. Months that worsened most: Nov (+13.9%). Months that improved most: Sep (-17.5%), Oct (-21%), Dec (-23.2%). Because Bilaspur's seasonal shape is flat year-round, policy action that targets the December peak buys disproportionate relief — most city-wide annual averages are dragged upwards by the worst two or three months.
Daily calendar heatmap
Every measured day for the last 3 years. Expand for the full 4-year archive.
Month-by-month deep dive
Tap any month to expand.
Jan2022–2024Latest AQI 96+46%
Jan in Bilaspur averages AQI 96 (Satisfactory) in the most recent year, having moved from 66 in 2022. Direction: worsening (+45.5%).
Feb2022–2024Latest AQI 60+9%
Feb in Bilaspur averages AQI 60 (Satisfactory) in the most recent year, having moved from 55 in 2022. Direction: stable (+9.1%).
Mar2022–2024Latest AQI 52-9%
Mar in Bilaspur averages AQI 52 (Satisfactory) in the most recent year, having moved from 57 in 2022. Direction: stable (-8.8%).
Apr2022–2024Latest AQI 58-5%
Apr in Bilaspur averages AQI 58 (Satisfactory) in the most recent year, having moved from 61 in 2022. Direction: stable (-4.9%).
May2022–2024Latest AQI 58+2%
May in Bilaspur averages AQI 58 (Satisfactory) in the most recent year, having moved from 57 in 2022. Direction: stable (+1.8%).
Jun2022–2024Latest AQI 48-21%
Jun in Bilaspur averages AQI 48 (Good) in the most recent year, having moved from 61 in 2022. Direction: improving (-21.3%).
Jul2022–2024Latest AQI 46-35%
Jul in Bilaspur averages AQI 46 (Good) in the most recent year, having moved from 71 in 2022. Direction: improving (-35.2%).
Aug2022–2024Latest AQI 43-34%
Aug in Bilaspur averages AQI 43 (Good) in the most recent year, having moved from 65 in 2022. Direction: improving (-33.8%).
Sep2021–2024Latest AQI 47-18%
Sep in Bilaspur averages AQI 47 (Good) in the most recent year, having moved from 57 in 2021. Direction: improving (-17.5%).
Oct2021–2024Latest AQI 64-21%
Oct in Bilaspur averages AQI 64 (Satisfactory) in the most recent year, having moved from 81 in 2021. Direction: improving (-21.0%).
Nov2021–2024Latest AQI 90+14%
Nov in Bilaspur averages AQI 90 (Satisfactory) in the most recent year, having moved from 79 in 2021. Direction: worsening (+13.9%).
Dec2021–2024Latest AQI 73-23%
Dec in Bilaspur averages AQI 73 (Satisfactory) in the most recent year, having moved from 95 in 2021. Direction: improving (-23.2%).
Cities with similar (and opposite) seasonal profiles
Ranked by cosine similarity of 12-month AQI signatures across monitored Indian cities.
Similar seasonal profile
Cities whose 12-month AQI signature most closely matches Bilaspur.
Opposite seasonal profile
Cities whose seasonal signature least resembles Bilaspur.
What to do with this information
If you are choosing when to visit Bilaspur or plan outdoor events — marathons, weddings, school sports, outdoor festivals — the CPCB record says September 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 December in Bilaspur 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 Bilaspur?
December is the most polluted month in Bilaspur on average, with a long-run AQI of 89 — firmly in the Satisfactory band. This is drawn from 1 CPCB monitoring stations across 4 years of daily readings. Through December, 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 Bilaspur?
September is the cleanest month of the year in Bilaspur, averaging AQI 54 in the Satisfactory band. The months immediately before and after also tend to sit well below the annual mean of 69, so a visit window centred on September 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 Bilaspur's air spike in December?
Bilaspur's profile is relatively flat year-round; the small December reflects modest swings in wind, rainfall and local emissions rather than a dramatic seasonal mechanism.
How bad is Diwali air quality in Bilaspur?
Across the CPCB record, the week around Diwali in Bilaspur averages AQI 85 — 1.12× the normal October baseline of AQI 75, a spike of 9 AQI points. Firework particulates combine with a cooler, more stagnant late-October atmosphere to produce some of the worst air-quality days of the entire year. Sensitive groups should treat Diwali eve and the two days after as peak-alert days: stay indoors, close windows by evening, run purifiers on high, and reserve any outdoor celebrations for daytime hours when mixing is strongest.
Does the monsoon actually clean Bilaspur's air?
Only partially. Bilaspur's monsoon window averages AQI 59, which is a 14.5% change from the annual mean of 69. Rain does scrub particulates, but the improvement here is modest — pointing to persistent local sources (industry, traffic, dust) that rain cannot fully wash away.
Is Bilaspur's worst season getting worse or better year-on-year?
Between 2021 and 2024, Bilaspur's annual average AQI moved from 83 to 61 — a change of -26.5%. In the most recent year-on-year comparison, the winter season specifically improved by 12.6%. The long-run direction is improving — NCAP policy pressure, cleaner fuels and tighter vehicle standards are showing up.
Which months are safest to visit Bilaspur?
September is the single best month at AQI 54. Based on the 12-month averages, the three cleanest months in Bilaspur are September (AQI 54), August (AQI 55), June (AQI 62). 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 December, when the baseline jumps into Satisfactory territory.
How does Bilaspur's seasonal pattern compare to other Indian cities?
Bilaspur is classified as flat year-round. Based on a 12-month cosine-similarity index computed across all monitored Indian cities, the city whose seasonal signature most closely resembles Bilaspur's is Puducherry (Puducherry), with its own worst month in December. Cities with similar signatures often respond to similar policy levers — if a neighbouring peer has demonstrated improvements through specific interventions (construction-dust controls, bus electrification, brick-kiln regulation), they are likely candidates for Bilaspur too. The peer-city panel on this page lists the closest four additional matches.