Silchar — Seasonal Pollution Patterns
Month-by-month air quality patterns for Silchar across 2 years of CPCB data. Based on CPCB station data, 2016–present.
Assam · Live Silchar AQI →
At a glance
Based on 2 years of CPCB monitoring across 1 stations, Silchar averages AQI 47 annually, with a pronounced seasonal pattern classified as flat year-round. The worst month is February at AQI 58 (Satisfactory) and the cleanest is June at AQI 39 (Good) — a 19-point swing between them. Severe days (AQI > 400) make up 0% of the record while Good-or-Satisfactory days account for 100.0%.
The four seasons
Indian meteorological seasons: Winter (Dec–Feb), Summer (Mar–May), Monsoon (Jun–Sep), Post-monsoon (Oct–Nov).
Winter
AQI 52Summer
AQI 50Monsoon
AQI 42Post-monsoon
AQI 45Climograph — 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2023 | 55 | 66 | 52 | 49 | 38 | 29 | 34 | 33 | 32 | 34 | 38 | 38 | 41 |
| 2024 | 49 | 50 | 53 | 51 | 55 | 48 | 50 | 53 | 52 | 55 | 53 | 58 | 52 |
| Avg | 51 | 58 | 53 | 50 | 46 | 39 | 42 | 43 | 42 | 45 | 46 | 48 | — |
Winter in Silchar
Winter (Dec–Jan–Feb) in Silchar averages AQI 52 across 160 measured days — Satisfactory on the NAQI scale. 0% of those days fall in Very Poor or Severe; 100% are Good or Satisfactory. Year-on-year, winter worsened by 1.2% in the most recent comparison. Winter in Silchar is not the headline season, but shallow morning inversions can still produce short spikes. Silchar'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 47 (Good), versus 44 (Good) for the rest of October. 14 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 43 (Good), compared with an annual mean of 47.
Summer
Summer (Mar–Apr–May) in Silchar averages AQI 50 across 178 measured days — Good on the NAQI scale. 0% of those days fall in Very Poor or Severe; 100% are Good or Satisfactory. Year-on-year, summer worsened by 14.5% in the most recent comparison. Summer air in Silchar 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. Silchar's summer mean of 50 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 Silchar averages AQI 42 across 235 measured days — Good on the NAQI scale. 0% of those days fall in Very Poor or Severe; 100% are Good or Satisfactory. Year-on-year, monsoon worsened by 59% in the most recent comparison. The Jul 15 – Sep 15 core monsoon window averages AQI 43, a 8.5% improvement on the annual mean of 47. 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 Silchar.
Post-monsoon
Post-monsoon (Oct–Nov) in Silchar averages AQI 45 across 119 measured days — Good on the NAQI scale. 0% of those days fall in Very Poor or Severe; 100% are Good or Satisfactory. Year-on-year, post-monsoon worsened by 48.3% in the most recent comparison. Post-monsoon in Silchar 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 2-year CPCB record.
First year vs latest year
Annual and per-season comparison.
Across the 2-year CPCB record Silchar is worsening overall — AQI moved from 41 in 2023 to 52 in 2024, a +26.8% change. No month shows a material worsening of 10% or more. No month shows a material improvement of 10% or more. Because Silchar's seasonal shape is flat year-round, policy action that targets the February 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 2 years. Expand for the full 2-year archive.
Month-by-month deep dive
Tap any month to expand.
Jan2023–2024Latest AQI 49-11%
Jan in Silchar averages AQI 49 (Good) in the most recent year, having moved from 55 in 2023. Direction: improving (-10.9%).
Feb2023–2024Latest AQI 50-24%
Feb in Silchar averages AQI 50 (Good) in the most recent year, having moved from 66 in 2023. Direction: improving (-24.2%).
Mar2023–2024Latest AQI 53+2%
Mar in Silchar averages AQI 53 (Satisfactory) in the most recent year, having moved from 52 in 2023. Direction: stable (+1.9%).
Apr2023–2024Latest AQI 51+4%
Apr in Silchar averages AQI 51 (Satisfactory) in the most recent year, having moved from 49 in 2023. Direction: stable (+4.1%).
May2023–2024Latest AQI 55+45%
May in Silchar averages AQI 55 (Satisfactory) in the most recent year, having moved from 38 in 2023. Direction: worsening (+44.7%).
Jun2023–2024Latest AQI 48+66%
Jun in Silchar averages AQI 48 (Good) in the most recent year, having moved from 29 in 2023. Direction: worsening (+65.5%).
Jul2023–2024Latest AQI 50+47%
Jul in Silchar averages AQI 50 (Good) in the most recent year, having moved from 34 in 2023. Direction: worsening (+47.1%).
Aug2023–2024Latest AQI 53+61%
Aug in Silchar averages AQI 53 (Satisfactory) in the most recent year, having moved from 33 in 2023. Direction: worsening (+60.6%).
Sep2023–2024Latest AQI 52+63%
Sep in Silchar averages AQI 52 (Satisfactory) in the most recent year, having moved from 32 in 2023. Direction: worsening (+62.5%).
Oct2023–2024Latest AQI 55+62%
Oct in Silchar averages AQI 55 (Satisfactory) in the most recent year, having moved from 34 in 2023. Direction: worsening (+61.8%).
Nov2023–2024Latest AQI 53+40%
Nov in Silchar averages AQI 53 (Satisfactory) in the most recent year, having moved from 38 in 2023. Direction: worsening (+39.5%).
Dec2023–2024Latest AQI 58+53%
Dec in Silchar averages AQI 58 (Satisfactory) in the most recent year, having moved from 38 in 2023. Direction: worsening (+52.6%).
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 Silchar.
Opposite seasonal profile
Cities whose seasonal signature least resembles Silchar.
What to do with this information
If you are choosing when to visit Silchar or plan outdoor events — marathons, weddings, school sports, outdoor festivals — the CPCB record says June 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 February in Silchar 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 Silchar?
February is the most polluted month in Silchar on average, with a long-run AQI of 58 — firmly in the Satisfactory band. This is drawn from 1 CPCB monitoring stations across 2 years of daily readings. Through February, 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 Silchar?
June is the cleanest month of the year in Silchar, averaging AQI 39 in the Good band. The months immediately before and after also tend to sit well below the annual mean of 47, so a visit window centred on June 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 Silchar's air spike in February?
Silchar's profile is relatively flat year-round; the small February reflects modest swings in wind, rainfall and local emissions rather than a dramatic seasonal mechanism.
How bad is Diwali air quality in Silchar?
Across the CPCB record, the week around Diwali in Silchar averages AQI 47 — 1.06× the normal October baseline of AQI 44, a spike of 3 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 Silchar's air?
Only partially. Silchar's monsoon window averages AQI 43, which is a 8.5% change from the annual mean of 47. 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 Silchar's worst season getting worse or better year-on-year?
Between 2023 and 2024, Silchar's annual average AQI moved from 41 to 52 — a change of +26.8%. In the most recent year-on-year comparison, the winter season specifically worsened by 1.2%. The long-run direction is worsening — rapid urbanisation and emissions growth appear to be outpacing efficiency gains.
Which months are safest to visit Silchar?
June is the single best month at AQI 39. Based on the 12-month averages, the three cleanest months in Silchar are June (AQI 39), July (AQI 42), September (AQI 42). 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 February, when the baseline jumps into Satisfactory territory.
How does Silchar's seasonal pattern compare to other Indian cities?
Silchar 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 Silchar's is Shivamogga (Karnataka), with its own worst month in February. 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 Silchar too. The peer-city panel on this page lists the closest four additional matches.