SmogRank / India / Bihar / Bettiah

Bettiah, month by month

Bettiah has a measured daily mean on 346 days since 21 February 2025. Its worst month was November 2025, at 153 US AQI (58.4 µg/m³), 137th of 2,715 cities on that month's world ranking. Its cleanest was August 2025, at 67 US AQI (17.8 µg/m³).

Every month since 2025

2026too few days for a mean (a year needs 200)155 days measured
Jan19 daysFeb17 daysMar82#410Apr19 daysMay16 daysJun13 daysJul2 daysAug19 daysSep20 daysOct5 days
2025too few days for a mean (a year needs 256)191 days measured
JanFeb5 daysMar129#106Apr98#132May8 daysJun13 daysJul9 daysAug67#249Sep17 daysOct13 daysNov153#137Dec151#170
Each square is a month's mean PM2.5 in US AQI from Bettiah's measured days, with its place on that month's world ranking under it. A month has a mean once 70% of its days are measured, the rule the monthly rankings use; under that, the square gives the days measured. Each square opens that month's ranking with Bettiah marked; each year, the year's.
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

Months without a mean, and why

15 months
MonthWhy
Oct 20265 of 12 days measured; a month needs 9. The others: 6 with no readings from the monitor, 1 with readings for part of the day (a day needs 18 hours).
Sep 202620 of 30 days measured; a month needs 21. The others: 1 with no readings from the monitor, 9 with readings for part of the day (a day needs 18 hours).
Aug 202619 of 31 days measured; a month needs 22. The others: 12 with under 18 hours of readings or readings that failed our checks.
Jul 20262 of 31 days measured; a month needs 22. The others: 29 with under 18 hours of readings or readings that failed our checks.
Jun 202613 of 30 days measured; a month needs 21. The others: 17 with under 18 hours of readings or readings that failed our checks.
May 202616 of 31 days measured; a month needs 22. The others: 15 with under 18 hours of readings or readings that failed our checks.
Apr 202619 of 30 days measured; a month needs 21. The others: 11 with under 18 hours of readings or readings that failed our checks.
Feb 202617 of 28 days measured; a month needs 20. The others: 11 with under 18 hours of readings or readings that failed our checks.
Jan 202619 of 31 days measured; a month needs 22. The others: 12 with under 18 hours of readings or readings that failed our checks.
Oct 202513 of 31 days measured; a month needs 22. The others: 18 with under 18 hours of readings or readings that failed our checks.
Sep 202517 of 30 days measured; a month needs 21. The others: 13 with under 18 hours of readings or readings that failed our checks.
Jul 20259 of 31 days measured; a month needs 22. The others: 22 with under 18 hours of readings or readings that failed our checks.
Jun 202513 of 30 days measured; a month needs 21. The others: 17 with under 18 hours of readings or readings that failed our checks.
May 20258 of 31 days measured; a month needs 22. The others: 23 with under 18 hours of readings or readings that failed our checks.
Feb 20255 of 28 days measured; a month needs 20. The others: 3 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.

Bettiah's worst months

MonthUS AQIDays measuredWorld rankEpisode
November 2025 15358.4 µg/m³25 of 30137thof 2,715–
December 2025 15156.0 µg/m³29 of 31170thof 3,006–
March 2025 12946.7 µg/m³23 of 31106thof 2,862Northern India, March and April 2025
India, March 2025
April 2025 9834.1 µg/m³21 of 30132ndof 2,951North-eastern India, April 2025
Northern India, March and April 2025
March 2026 8225.6 µg/m³25 of 31410thof 2,971–
August 2025 6717.8 µg/m³28 of 31249thof 2,901–

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.

Bettiah's worst days

DayUS AQIEpisode
16 May 2026 491321.0 µg/m³Northern India, May 2026
18 May 2026 245170.0 µg/m³Northern India, May 2026
6 Jan 2026 184102.0 µg/m³–
5 Jan 2026 17792.3 µg/m³–
2 Jan 2026 17690.6 µg/m³–
14 May 2026 17488.9 µg/m³–
25 Oct 2025 17386.7 µg/m³India and Pakistan, October 2025
1 Jan 2026 17183.4 µg/m³–
26 Dec 2025 17082.8 µg/m³–
25 Dec 2025 16879.9 µg/m³–

Daily means, the highest since 21 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, Bettiah, India, 21 Feb 2025 – 6 Oct 2026. Monitor data from CPCB via OpenAQ; sources listed at smogrank.com/sources. smogrank.com/in/bettiah/history (accessed 12 Oct 2026).

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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.

Bettiah now: the last 24 hours, its ranks today and the last 12 months day by day.

Updated 2026-10-12 20:07 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).