SmogRank / Episodes / India
South-western India, October 2025
For 3 days, from 12 to 14 October 2025, 12 cities in India had PM2.5 at least twice their usual for the time of year. The worst reading was Chittoor, Andhra Pradesh, India: 114.0 µg/m³ on 12 October, about 2.5× its usual 44.8.
No cause named We have no fire or smoke records for these days, so we only say what the measurements show.
Cities reached 12 in 1 country
Days 3 12 to 14 October 2025
Worst day 12 October 9 cities counted
Furthest above usual 7.7× Tiruppur
Day by day
Play 12 October 9 cities at twice their usual or more
Karur Perundurai Tiruchirappalli Ariyalūr Ooty Gudalur Thrissur Nagapattinam Cuddalore Bengaluru Alangad Rānipet Tirunelveli Kanchipuram Kollam Gūduvāncheri Uliyazhathura Kannur Tambaram Tirupati Chennai Gummidipundi Shivamogga Dindigul Ramanathapuram Closepet Puducherry Chittoor Thiruvananthapuram Coimbatore Chikmagalūr Neelankarai Madikeri Tirumala Tiruppur 9 Oct 10 11 12 13 14 15 16 17 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
Tirumala Tirumala, 9 October: 35.7 µg/m³, 2.6× usual Tirumala, 10 October: 45.3 µg/m³, 3.3× usual Tirumala, 11 October: 50.3 µg/m³, 3.6× usual Tirumala, 12 October: 58.6 µg/m³, 4.2× usual Tirumala, 13 October: 34.5 µg/m³, 2.5× usual Tirumala, 14 October: 28.8 µg/m³, 2.1× usual Tirumala, 15 October: 17.9 µg/m³, 1.3× usual Tirumala, 16 October: 15.0 µg/m³, 1.1× usual Tirumala, 17 October: 11.1 µg/m³, 0.8× usual Tiruppur Tiruppur, 9 October: no reading Tiruppur, 10 October: 23.0 µg/m³, 2.0× usual Tiruppur, 11 October: 48.1 µg/m³, 4.3× usual Tiruppur, 12 October: 86.7 µg/m³, 7.7× usual Tiruppur, 13 October: 58.8 µg/m³, 5.2× usual Tiruppur, 14 October: 44.1 µg/m³, 3.9× usual Tiruppur, 15 October: 27.1 µg/m³, 2.4× usual Tiruppur, 16 October: 19.9 µg/m³, 1.8× usual Tiruppur, 17 October: 29.8 µg/m³, 2.6× usual Chittoor Chittoor, 9 October: 81.8 µg/m³, 1.8× usual Chittoor, 10 October: 67.4 µg/m³, 1.5× usual Chittoor, 11 October: no reading Chittoor, 12 October: 114.0 µg/m³, 2.5× usual Chittoor, 13 October: 92.7 µg/m³, 2.1× usual Chittoor, 14 October: 51.3 µg/m³, 1.1× usual Chittoor, 15 October: no reading Chittoor, 16 October: 39.7 µg/m³, 0.9× usual Chittoor, 17 October: no reading Madikeri Madikeri, 9 October: 12.7 µg/m³, 0.9× usual Madikeri, 10 October: 12.7 µg/m³, 0.9× usual Madikeri, 11 October: 17.2 µg/m³, 1.2× usual Madikeri, 12 October: 61.8 µg/m³, 4.2× usual Madikeri, 13 October: 50.0 µg/m³, 3.4× usual Madikeri, 14 October: 39.9 µg/m³, 2.7× usual Madikeri, 15 October: 13.0 µg/m³, 0.9× usual Madikeri, 16 October: 15.1 µg/m³, 1.0× usual Madikeri, 17 October: 6.8 µg/m³, 0.5× usual Puducherry Puducherry, 9 October: no reading Puducherry, 10 October: 12.7 µg/m³, 0.7× usual Puducherry, 11 October: 30.8 µg/m³, 1.7× usual Puducherry, 12 October: 42.3 µg/m³, 2.3× usual Puducherry, 13 October: 32.2 µg/m³, 1.8× usual Puducherry, 14 October: 15.7 µg/m³, 0.9× usual Puducherry, 15 October: 6.7 µg/m³, 0.4× usual Puducherry, 16 October: 6.6 µg/m³, 0.4× usual Puducherry, 17 October: 5.3 µg/m³, 0.3× usual Neelankarai Neelankarai, 9 October: no reading Neelankarai, 10 October: no reading Neelankarai, 11 October: 33.5 µg/m³, 1.6× usual Neelankarai, 12 October: 41.9 µg/m³, 2.0× usual Neelankarai, 13 October: 72.2 µg/m³, 3.4× usual Neelankarai, 14 October: 53.5 µg/m³, 2.5× usual Neelankarai, 15 October: 7.4 µg/m³, 0.4× usual Neelankarai, 16 October: 12.5 µg/m³, 0.6× usual Neelankarai, 17 October: 8.0 µg/m³, 0.4× usual Closepet Closepet, 9 October: no reading Closepet, 10 October: no reading Closepet, 11 October: 22.7 µg/m³, 1.3× usual Closepet, 12 October: 40.0 µg/m³, 2.2× usual Closepet, 13 October: 39.6 µg/m³, 2.2× usual Closepet, 14 October: 25.9 µg/m³, 1.4× usual Closepet, 15 October: 19.1 µg/m³, 1.1× usual Closepet, 16 October: 13.2 µg/m³, 0.7× usual Closepet, 17 October: no reading Chikmagalūr Chikmagalūr, 9 October: no reading Chikmagalūr, 10 October: no reading Chikmagalūr, 11 October: 16.2 µg/m³, 1.3× usual Chikmagalūr, 12 October: 34.6 µg/m³, 2.8× usual Chikmagalūr, 13 October: 37.8 µg/m³, 3.0× usual Chikmagalūr, 14 October: 20.7 µg/m³, 1.7× usual Chikmagalūr, 15 October: no reading Chikmagalūr, 16 October: 13.0 µg/m³, 1.0× usual Chikmagalūr, 17 October: 8.7 µg/m³, 0.7× usual Thiruvananthapuram Thiruvananthapuram, 9 October: 17.4 µg/m³, 1.6× usual Thiruvananthapuram, 10 October: 13.4 µg/m³, 1.2× usual Thiruvananthapuram, 11 October: 14.1 µg/m³, 1.3× usual Thiruvananthapuram, 12 October: 28.8 µg/m³, 2.6× usual Thiruvananthapuram, 13 October: 6.4 µg/m³, 0.6× usual Thiruvananthapuram, 14 October: 15.7 µg/m³, 1.4× usual Thiruvananthapuram, 15 October: 25.2 µg/m³, 2.3× usual Thiruvananthapuram, 16 October: 20.4 µg/m³, 1.8× usual Thiruvananthapuram, 17 October: 20.6 µg/m³, 1.8× usual Coimbatore Coimbatore, 9 October: 43.3 µg/m³, 1.7× usual Coimbatore, 10 October: 41.6 µg/m³, 1.6× usual Coimbatore, 11 October: 34.8 µg/m³, 1.4× usual Coimbatore, 12 October: 38.7 µg/m³, 1.5× usual Coimbatore, 13 October: 46.5 µg/m³, 1.8× usual Coimbatore, 14 October: 77.6 µg/m³, 3.0× usual Coimbatore, 15 October: 47.0 µg/m³, 1.8× usual Coimbatore, 16 October: 42.4 µg/m³, 1.6× usual Coimbatore, 17 October: 45.1 µg/m³, 1.8× usual Ramanathapuram Ramanathapuram, 9 October: 50.8 µg/m³, 1.5× usual Ramanathapuram, 10 October: 19.7 µg/m³, 0.6× usual Ramanathapuram, 11 October: 34.9 µg/m³, 1.0× usual Ramanathapuram, 12 October: 13.1 µg/m³, 0.4× usual Ramanathapuram, 13 October: 23.1 µg/m³, 0.7× usual Ramanathapuram, 14 October: 73.0 µg/m³, 2.1× usual Ramanathapuram, 15 October: 115.0 µg/m³, 3.4× usual Ramanathapuram, 16 October: 10.2 µg/m³, 0.3× usual Ramanathapuram, 17 October: no reading Dindigul Dindigul, 9 October: 21.5 µg/m³, 1.3× usual Dindigul, 10 October: 23.6 µg/m³, 1.4× usual Dindigul, 11 October: 20.7 µg/m³, 1.2× usual Dindigul, 12 October: 26.3 µg/m³, 1.5× usual Dindigul, 13 October: 32.5 µg/m³, 1.9× usual Dindigul, 14 October: 34.6 µg/m³, 2.0× usual Dindigul, 15 October: 19.5 µg/m³, 1.1× usual Dindigul, 16 October: no reading Dindigul, 17 October: no reading 9 Oct 10 11 12 13 14 15 16 17 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. Good 0–50
Moderate 51–100
Sensitive groups 101–150
Unhealthy 151–200
Very unhealthy 201–300
Hazardous 301+
Every city it reached
City Days Highest Usual Above usual
Tiruppur Tamil Nadu, India 3 12 October 11.3 7.7× Madikeri Karnataka, India 3 12 October 14.6 4.2× Tirumala Andhra Pradesh, India 2 12 October 13.9 4.2× Neelankarai Tamil Nadu, India 2 13 October 21.0 3.4× Ramanathapuram Tamil Nadu, India 1 15 October 34.0 3.4× Chikmagalūr Karnataka, India 2 13 October 12.4 3.0× Coimbatore Tamil Nadu, India 1 14 October 25.7 3.0× Thiruvananthapuram Kerala, India 1 12 October 11.2 2.6× Chittoor Andhra Pradesh, India 2 12 October 44.8 2.5× Puducherry Puducherry, India 1 12 October 18.2 2.3× Closepet Karnataka, India 1 12 October 17.9 2.2× Dindigul Tamil Nadu, India 1 14 October 17.0 2.0×
Daily means in µg/m³. Usual: the city's median for this time of year (its days within 21 days of the date, every year, leaving out the week around it). Above usual: its highest day against that.
Against other episodes in India
Number 29 of 54 episodes in India since our records began, by cities reached.
North-western India, October 2025 170 North-western India, September 2026 57 North-western India, July 2026 51 North-western India, June 2025 47 North-eastern India, March and April 2025 45 North-western India, November 2025 27 North-western India, April 2026 26 North-western India, April and May 2025 26 North-western India and Pakistan, March 2026 25 North-western India, May 2025 23 North-eastern India, July 2026 22 North-eastern India, April 2025 20 South-western India, October 2025 12 Bars: cities reached; colour: the level of the episode's highest daily reading. All 54 .
Use this page SmogRank, South-western India, October 2025: 12 cities with PM2.5 at twice their usual or more, 12 to 14 October 2025, smogrank.com/episodes/2025-10-south-western-india (accessed 2 October 2026).
Copy citation Download top 10 (PNG)
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.
