SmogRank / Episodes / India

South-western India, 7 to 8 October 2025

For 2 days, from 7 to 8 October 2025, 9 cities in India had PM2.5 at least twice their usual for the time of year. The worst reading was Chittoor, Andhra Pradesh, India: 96.8 µg/m³ on 8 October, about 2.3× its usual 42.0.

No cause namedWe have no fire or smoke records for these days, so we only say what the measurements show.
Cities reached9in 1 country
Days27 to 8 October 2025
Worst day7 October6 cities counted
Furthest above usual3.5×Tiruppur

Day by day

7 October 6 cities at twice their usual or more
SalemTiruchirappalliNavalpattuCoimbatoreAriyalūrTirupparangunramOotyGudalurClosepetThrissurAlangadBengaluruRamanathapuramNagapattinamCuddalorePuducherryRānipetTirunelveliKanchipuramKollamKannurUliyazhathuraGūduvāncheriTirupatiNeelankaraiChennaiChikmagalūrGummidipundiShivamoggaPerunduraiKarurDindigulChittoorTirumalaTambaramThiruvananthapuramMadikeriTiruppur
4 Oct567891011
Every measured city in the area, coloured by its PM2.5 that day; a dark ring marks a city at twice its usual or more. Bars: cities counted each day, coloured by their median level. Choose a day or press play; without JavaScript, the days link to that day's world ranking.

How it spread

TiruppurTiruppur, 4 October: no readingTiruppur, 5 October: no readingTiruppur, 6 October: 8.1 µg/m³Tiruppur, 7 October: 53.6 µg/m³, 3.5× its usual 15.2Tiruppur, 8 October: 13.5 µg/m³Tiruppur, 9 October: no readingTiruppur, 10 October: 23.0 µg/m³Tiruppur, 11 October: 48.1 µg/m³MadikeriMadikeri, 4 October: 16.9 µg/m³Madikeri, 5 October: 25.9 µg/m³Madikeri, 6 October: 36.2 µg/m³Madikeri, 7 October: 37.1 µg/m³, 3.4× its usual 10.8Madikeri, 8 October: 27.9 µg/m³, 2.4× its usual 11.5Madikeri, 9 October: 12.7 µg/m³Madikeri, 10 October: 12.7 µg/m³Madikeri, 11 October: 17.2 µg/m³ThiruvananthapuramThiruvananthapuram, 4 October: 12.6 µg/m³Thiruvananthapuram, 5 October: 15.7 µg/m³Thiruvananthapuram, 6 October: 18.2 µg/m³Thiruvananthapuram, 7 October: 35.2 µg/m³, 3.0× its usual 11.7Thiruvananthapuram, 8 October: 23.8 µg/m³Thiruvananthapuram, 9 October: 17.4 µg/m³Thiruvananthapuram, 10 October: 13.4 µg/m³Thiruvananthapuram, 11 October: 14.1 µg/m³TirumalaTirumala, 4 October: 14.7 µg/m³Tirumala, 5 October: 15.5 µg/m³Tirumala, 6 October: 16.4 µg/m³Tirumala, 7 October: 34.3 µg/m³, 2.5× its usual 13.5Tirumala, 8 October: 34.0 µg/m³, 2.4× its usual 13.9Tirumala, 9 October: 35.7 µg/m³Tirumala, 10 October: 45.3 µg/m³Tirumala, 11 October: 50.3 µg/m³TambaramTambaram, 4 October: 17.2 µg/m³Tambaram, 5 October: 22.0 µg/m³Tambaram, 6 October: 24.3 µg/m³Tambaram, 7 October: 28.0 µg/m³, 2.7× its usual 10.3Tambaram, 8 October: 30.4 µg/m³, 3.0× its usual 10.3Tambaram, 9 October: 31.6 µg/m³Tambaram, 10 October: 24.5 µg/m³Tambaram, 11 October: no readingKarurKarur, 4 October: 33.3 µg/m³Karur, 5 October: 35.6 µg/m³Karur, 6 October: 19.1 µg/m³Karur, 7 October: 27.6 µg/m³, 2.0× its usual 13.8Karur, 8 October: 21.9 µg/m³Karur, 9 October: 13.6 µg/m³Karur, 10 October: 16.0 µg/m³Karur, 11 October: 13.8 µg/m³ChittoorChittoor, 4 October: no readingChittoor, 5 October: no readingChittoor, 6 October: 48.8 µg/m³Chittoor, 7 October: 56.9 µg/m³Chittoor, 8 October: 96.8 µg/m³, 2.3× its usual 42.0Chittoor, 9 October: 81.8 µg/m³Chittoor, 10 October: 67.4 µg/m³Chittoor, 11 October: no readingDindigulDindigul, 4 October: 16.9 µg/m³Dindigul, 5 October: 12.5 µg/m³Dindigul, 6 October: 17.7 µg/m³Dindigul, 7 October: 28.7 µg/m³Dindigul, 8 October: 33.2 µg/m³, 2.1× its usual 16.0Dindigul, 9 October: 21.5 µg/m³Dindigul, 10 October: 23.6 µg/m³Dindigul, 11 October: 20.7 µg/m³PerunduraiPerundurai, 4 October: no readingPerundurai, 5 October: no readingPerundurai, 6 October: no readingPerundurai, 7 October: 27.0 µg/m³Perundurai, 8 October: 27.5 µg/m³, 2.0× its usual 13.7Perundurai, 9 October: 21.5 µg/m³Perundurai, 10 October: 16.2 µg/m³Perundurai, 11 October: 30.4 µg/m³4 Oct567891011
Every counted city, in the order the episode reached them, 3 days before to 3 after. Each square is a day, coloured by that day's PM2.5; outlined: at twice the city's usual or more.
Good0–50
Moderate51–100
Sensitive groups101–150
Unhealthy151–200
Very unhealthy201–300
Hazardous301+

Every city it reached

CityDaysHighestUsualAbove usual
TiruppurTamil Nadu, India1 53.67 October15.23.5×
MadikeriKarnataka, India2 37.17 October10.83.4×
ThiruvananthapuramKerala, India1 35.27 October11.73.0×
TambaramTamil Nadu, India2 30.48 October10.33.0×
TirumalaAndhra Pradesh, India2 34.37 October13.52.5×
ChittoorAndhra Pradesh, India1 96.88 October42.02.3×
DindigulTamil Nadu, India1 33.28 October16.02.1×
KarurTamil Nadu, India1 27.67 October13.82.0×
PerunduraiTamil Nadu, India1 27.58 October13.72.0×

Daily means in µg/m³, over the days each city counted in this episode. Highest: its highest of those days. Usual: the city's median for the time of year of that day (its days within 21 days of the date, every year, leaving out the week around it). Above usual: its highest day against that, with a usual under 5 µg/m³ taken as 5.

Against other episodes in India

Number 45 of 54 episodes in India since our records began, by cities reached.

Bars: cities reached; colour: the level of the episode's highest daily reading. All 54.

Use this page

SmogRank, South-western India, 7 to 8 October 2025: 9 cities with PM2.5 at twice their usual or more, 7 to 8 October 2025, smogrank.com/episodes/2025-10-07-south-western-india (accessed 4 October 2026).

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You're welcome to reuse a single chart, image or figure with this citation and a link. Terms.

An episode is a run of days when many cities close to each other (four or more within 350 km on a day, 8 or more in all) each had a daily PM2.5 mean of at least 25 µg/m³ and at least 2 times their usual for that time of year. Found in our own measurements, not picked by hand. How we find episodes. Values are each city's daily mean of its own monitors; causes are the usual kinds for a pattern like this, not a confirmed source.