SmogRank / India / Arunachal Pradesh / Naharlagun

Naharlagun, month by month

Naharlagun has a measured daily mean on 364 days since 26 February 2025. Its worst month was February 2026, at 173 US AQI (87.5 µg/m³), 21st of 2,866 cities on that month's world ranking. Its cleanest was August 2026, at 65 US AQI (16.6 µg/m³).

Every month since 2025

2026too few days for a mean (a year needs 200)198 days measured
Jan19 daysFeb173#21Mar20 daysApr20 daysMay76#250Jun20 daysJul15 daysAug65#335Sep69#285Oct6 days
2025too few days for a mean (a year needs 256)166 days measured
JanFeb3 daysMar14 daysApr11 daysMay10 daysJun3 daysJul7 daysAug21 daysSep66#276Oct75#258Nov17 daysDec162#103
Each square is a month's mean PM2.5 in US AQI from Naharlagun'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 Naharlagun 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

14 months
MonthWhy
Oct 20266 of 12 days measured; a month needs 9. The others: 5 with no readings from the monitor, 1 with readings for part of the day (a day needs 18 hours).
Jul 202615 of 31 days measured; a month needs 22. The others: 16 with under 18 hours of readings or readings that failed our checks.
Jun 202620 of 30 days measured; a month needs 21. The others: 10 with under 18 hours of readings or readings that failed our checks.
Apr 202620 of 30 days measured; a month needs 21. The others: 10 with under 18 hours of readings or readings that failed our checks.
Mar 202620 of 31 days measured; a month needs 22. 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.
Nov 202517 of 30 days measured; a month needs 21. The others: 13 with under 18 hours of readings or readings that failed our checks.
Aug 202521 of 31 days measured; a month needs 22. The others: 10 with under 18 hours of readings or readings that failed our checks.
Jul 20257 of 31 days measured; a month needs 22. The others: 24 with under 18 hours of readings or readings that failed our checks.
Jun 20253 of 30 days measured; a month needs 21. The others: 27 with under 18 hours of readings or readings that failed our checks.
May 202510 of 31 days measured; a month needs 22. The others: 21 with under 18 hours of readings or readings that failed our checks.
Apr 202511 of 30 days measured; a month needs 21. The others: 19 with under 18 hours of readings or readings that failed our checks.
Mar 202514 of 31 days measured; a month needs 22. The others: 17 with under 18 hours of readings or readings that failed our checks.
Feb 20253 of 28 days measured; a month needs 20.

A day counts once 18 hours of it are measured; a month needs 70% of its days.

Naharlagun's worst months

MonthUS AQIDays measuredWorld rank
February 2026 17387.5 µg/m³21 of 2821stof 2,866
December 2025 16271.6 µg/m³28 of 31103rdof 3,006
May 2026 7622.3 µg/m³24 of 31250thof 2,874
October 2025 7521.8 µg/m³27 of 31258thof 2,614
September 2026 6919.0 µg/m³25 of 30285thof 2,981
September 2025 6617.4 µg/m³25 of 30276thof 3,104

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.

Naharlagun's worst days

DayUS AQI
21 Feb 2026 214139.0 µg/m³
20 Feb 2026 210135.0 µg/m³
25 Jan 2026 192114.0 µg/m³
16 Dec 2025 191113.0 µg/m³
13 Dec 2025 191112.0 µg/m³
9 Feb 2026 191112.0 µg/m³
27 Jan 2026 189109.0 µg/m³
1 Feb 2026 188108.0 µg/m³
12 Feb 2026 187107.0 µg/m³
29 Jan 2026 184103.0 µg/m³

Daily means, the highest since 26 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, Naharlagun, India, 26 Feb 2025 – 7 Oct 2026. Monitor data from CPCB via OpenAQ; sources listed at smogrank.com/sources. smogrank.com/in/naharlagun/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.

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

Updated 2026-10-12 22:07 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).