SmogRank / India / Bihar / Katihar
Katihar, month by month
Katihar has a measured daily mean on 433 days since 22 February 2025. Its worst month was December 2025, at 157 US AQI (64.7 µg/m³), 124th of 3,006 cities on that month's world ranking. Its cleanest was July 2026, at 53 US AQI (10.3 µg/m³).
Every month since 2025
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
Months without a mean, and why
8 months
| Month | Why |
|---|---|
| Oct 2026 | 3 of 12 days measured; a month needs 9. The others: 5 with no readings from the monitor, 3 with readings for part of the day (a day needs 18 hours), 1 with under 18 hours of readings or readings that failed our checks. |
| Aug 2026 | 14 of 31 days measured; a month needs 22. The others: 17 with under 18 hours of readings or readings that failed our checks. |
| Jan 2026 | 20 of 31 days measured; a month needs 22. The others: 11 with under 18 hours of readings or readings that failed our checks. |
| Jul 2025 | 15 of 31 days measured; a month needs 22. The others: 16 with under 18 hours of readings or readings that failed our checks. |
| Jun 2025 | 16 of 30 days measured; a month needs 21. The others: 14 with under 18 hours of readings or readings that failed our checks. |
| May 2025 | 15 of 31 days measured; a month needs 22. The others: 16 with under 18 hours of readings or readings that failed our checks. |
| Apr 2025 | 15 of 30 days measured; a month needs 21. The others: 15 with under 18 hours of readings or readings that failed our checks. |
| Feb 2025 | 6 of 28 days measured; a month needs 20. The others: 1 with under 18 hours of readings or readings that failed our checks. |
A day counts once 18 hours of it are measured; a month needs 70% of its days.
Katihar's worst months
| Month | US AQI | World rank | Episode |
|---|---|---|---|
| December 2025 | 15764.7 µg/m³ | 124thof 3,006 | – |
| November 2025 | 12344.6 µg/m³ | 192ndof 2,715 | – |
| February 2026 | 10938.6 µg/m³ | 162ndof 2,866 | – |
| March 2025 | 10436.7 µg/m³ | 201stof 2,862 | Northern India, March and April 2025 |
| October 2025 | 9934.8 µg/m³ | 172ndof 2,614 | India and Pakistan, October 2025 |
| March 2026 | 8627.8 µg/m³ | 338thof 2,971 | India, March 2026 |
Monthly means over the days measured; finished months only. World rank: its place on that month's world ranking of every city with enough days. Each month opens that ranking.
Katihar's worst days
| Day | US AQI | Episode |
|---|---|---|
| 2 Jan 2026 | 18197.9 µg/m³ | – |
| 25 Dec 2025 | 18096.3 µg/m³ | – |
| 6 Jan 2026 | 17691.3 µg/m³ | – |
| 26 Dec 2025 | 17589.6 µg/m³ | – |
| 1 Jan 2026 | 17589.6 µg/m³ | – |
| 24 Dec 2025 | 17589.1 µg/m³ | – |
| 9 Dec 2025 | 17184.0 µg/m³ | – |
| 20 Oct 2025 | 16980.7 µg/m³ | India and Pakistan, October 2025 |
| 11 Dec 2025 | 16778.5 µg/m³ | – |
| 8 Dec 2025 | 16677.6 µg/m³ | – |
Daily means, the highest since 22 Feb 2025; the WHO's daily guideline is 15 µg/m³. Each date opens that day's world ranking, and each episode the bad-air spell it was part of.
Use this history
SmogRank, PM2.5 monthly and daily means, Katihar, India, 22 Feb 2025 – 5 Oct 2026. Monitor data from CPCB via OpenAQ; sources listed at smogrank.com/sources. smogrank.com/in/katihar/history (accessed 12 Oct 2026).
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.
Katihar now: the last 24 hours, its ranks today and the last 12 months day by day.
Updated 2026-10-12 18:07 UTC. Values are PM2.5 (fine particles), the median of each city's monitors, as the US AQI PM2.5 sub-index. Some low-cost readings: Sensor.Community, ODbL (data and licence). Some readings: Uzhydromet (Uzbekistan's Hydrometeorological Service); Department of Environment, Nepal; Vietnam's government monitors; Aurassure; Umhverfisstofnun (Environment Agency of Iceland); RMCAB (Secretaría Distrital de Ambiente, Bogotá); Love My Air (City and County of Denver), no reuse terms published (why we use them).