SmogRank / World / Asia / India / Bihar
Most polluted cities in Bihar, India
11 measured cities, last 30 days; 11 above the WHO 24-hour guideline. Worst: Arāria at 39.9 µg/m³, #59 in the world.
464 monitors in India haven't reported for more than two days. Cities that rely on them are missing from the 24-hour board and may drop from the longer ones; that isn't clean air, and they return when the data does.
About 133K people in these 3 cities breathed unhealthy air on an average day over the last 30 days.
Ranked by people: each city's population times its share of unhealthy days, those with a daily mean over 35.4 µg/m³ (US AQI 101+). That is how many people living there breathed unhealthy air on an average day. Only cities measured at 2 or more places at least 3 km apart are ranked: one monitor shouldn't speak for a whole city. Population is the city itself, not its wider metro area.
- 1Gayalast full day 30 Sept 133K
- 2Patnalast full day 30 Sept 0
- 3Muzaffarpurlast full day 30 Sept 0
The US EPA's Air Quality Index for PM2.5 (2024 breakpoints). Show values as: µg/m³ · US AQI · India AQI · China AQI · European AQI · UK DAQI · Canada AQHI+. About the scales
Estimated: cities without a monitor
Bihar cities we can't measure, with model estimates for the last 7 days. Listed by population, not ranked: estimates aren't precise enough to rank. Model estimates from the Copernicus Atmosphere Monitoring Service (CAMS), adjusted to measured cities nearby where there are any. Adjusted, a single day lands within ×1.5 of what a monitor would read about two times in three; unadjusted, it can be off by half or double. Treat them as a guide, not a measurement.
| City | 7-day estimate |
|---|---|
| Darbhanga | ≈ 59 µg/m³ |
| Dinapur Nizamat | ≈ 55 µg/m³ |
| Dinapore | ≈ 55 µg/m³ |
| Madhurampur Dehri | ≈ 47 µg/m³ |
| Bagaha | ≈ 43 µg/m³ |
| Jamālpur | ≈ 48 µg/m³ |
| Jahānābād | ≈ 57 µg/m³ |
| Aurangābād | ≈ 53 µg/m³ |
| Luckeesarai | ≈ 52 µg/m³ |
| Nawāda | ≈ 45 µg/m³ |
| Bagaha | ≈ 36 µg/m³ |
| Jamūī | ≈ 40 µg/m³ |
| Bāruni | ≈ 53 µg/m³ |
| Phulwari Sharif | ≈ 55 µg/m³ |
| Madhubani | ≈ 70 µg/m³ |
| Benipur | ≈ 59 µg/m³ |
| Barauni | ≈ 53 µg/m³ |
| Bihāt | ≈ 53 µg/m³ |
| Sītāmarhi | ≈ 67 µg/m³ |
| Gopālganj | ≈ 67 µg/m³ |
| Supaul | ≈ 57 µg/m³ |
| Sheikhpura | ≈ 52 µg/m³ |
| Bārh | ≈ 54 µg/m³ |
| Mokameh | ≈ 52 µg/m³ |
| Bangaon | ≈ 57 µg/m³ |
| Masaurhi Buzurg | ≈ 53 µg/m³ |
| Teghra | ≈ 53 µg/m³ |
| Raxaul | ≈ 67 µg/m³ |
| Madhepura | ≈ 59 µg/m³ |
| Dumraon | ≈ 59 µg/m³ |
| Sultānganj | ≈ 50 µg/m³ |
| Daudnagar | ≈ 57 µg/m³ |
| Arwal | ≈ 57 µg/m³ |
| Khagaul | ≈ 55 µg/m³ |
| Hilsa | ≈ 53 µg/m³ |
| Fatwa | ≈ 55 µg/m³ |
| Forbesganj | ≈ 73 µg/m³ |
| Bhabhua | ≈ 48 µg/m³ |
| Khagaria | ≈ 52 µg/m³ |
| Narkatiāganj | ≈ 44 µg/m³ |
Bad-air episodes in Bihar
- Eastern India, 28 September to 1 October 20264 days15 cities85 µg/m³peak, Dera Colliery Township
- North-eastern India and Bhutan, September 20264 to 9 September 2026, 6 days15 cities107 µg/m³peak, Bihār Sharīf
- Bihar, Odisha and Uttar Pradesh, India, August 202621 to 23 August 2026, 3 days10 cities208 µg/m³peak, Sasarām
- North-eastern India, July 202611 to 14 July 2026, 4 days23 cities149 µg/m³peak, Arrah
- Northern India, May 202616 to 21 May 2026, 6 days17 cities321 µg/m³peak, Bettiah
- Eastern India, April 202623 to 25 April 2026, 3 days14 cities145 µg/m³peak, Singrauli
Times when many cities around here had PM2.5 at twice their usual or more on the same days.
Use this board
SmogRank, most polluted cities in Bihar, India, PM2.5, last 30 days to 6 Oct 2026, 22:00 UTC, smogrank.com/in/region/bihar?w=30d.
You're welcome to reuse a single chart, image or figure with this citation and a link. Terms. Raw monitor readings in bulk are published by OpenAQ, under each provider's licence.
Updated 2026-10-06 22:07 UTC. Values are PM2.5 (fine particles), the median of each city's monitors, as the US AQI PM2.5 sub-index.