SmogRank / World / India / Bihar / April 2026

Most polluted cities in Bihar, India, April 2026

16 cities in Bihar, India ranked by their average PM2.5 over the 30 days. Worst: Hājīpur at 66.3 µg/m³, #28 of 2,914 cities in the world. Cleanest: Katihar at 18.8. A city needs measurements on 70% of the days to be ranked.

Ranked by unhealthy days: the share of each city's measured days with a daily mean over 35.4 µg/m³ (US AQI 101+), Unhealthy for Sensitive Groups or worse on the US EPA's scale. Ties go to the higher average.

← Muzaffarpur 97% 90%0
Every city in Bihar, India ranked for April 2026, one column each, ranked by unhealthy days: height is the share of its measured days that were unhealthy, colour its average. Point at it to read a city; tap to open it.
  1. 1Muzaffarpur
    97%
  2. 2Hājīpur
    96%
  3. 3Purnia
    87%
  4. 4Mothīhāri
    81%
  5. 5Patna
    79%
  6. 6Arrah
    60%
  7. 7Gaya
    59%
  8. 8Begusarai
    50%
  9. 9Arāria
    48%
  10. 10Bhāgalpur
    43%
  11. 11Siwān
    29%
  12. 12Rājgīr
    26%
  13. 13Munger
    15%
  14. 14Bihār Sharīf
    12%
  15. 15Kishanganj
    7%
  16. 16Katihar
    0%
Good0–50
Moderate51–100
Sensitive groups101–150
Unhealthy151–200
Very unhealthy201–300
Hazardous301+

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

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SmogRank, most polluted cities in Bihar, India, PM2.5, April 2026, smogrank.com/in/region/bihar/history/2026-04 (accessed 6 Oct 2026).

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