SmogRank / India / Sikkim / Gangtok

Gangtok, month by month

Gangtok has a measured daily mean on 368 days since 19 February 2025. Its worst month was March 2026, at 80 US AQI (24.8 µg/m³), 431st of 2,971 cities on that month's world ranking. Its cleanest was August 2025, at 37 US AQI (6.6 µg/m³).

Every month since 2025

2026too few days for a mean (a year needs 199)153 days measured
Jan12 daysFeb17 daysMar80#431Apr76#359May63#395Jun67#278Jul6 daysAug5 daysSep5 daysOct4 days
2025too few days for a mean (a year needs 256)215 days measured
JanFeb8 daysMar18 daysApr9 daysMay19 daysJun19 daysJul55#961Aug37#2,326Sep43#1,343Oct52#572Nov20 daysDec10 days
Each square is a month's mean PM2.5 in US AQI from Gangtok'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 Gangtok 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

13 months
MonthWhy
Oct 20264 of 11 days measured; a month needs 8. The others: 5 with no readings from the monitor, 2 with readings for part of the day (a day needs 18 hours).
Sep 20265 of 30 days measured; a month needs 21. The others: 25 with readings for part of the day (a day needs 18 hours).
Aug 20265 of 31 days measured; a month needs 22. The others: 26 with under 18 hours of readings or readings that failed our checks.
Jul 20266 of 31 days measured; a month needs 22. The others: 25 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 202612 of 31 days measured; a month needs 22. The others: 19 with under 18 hours of readings or readings that failed our checks.
Dec 202510 of 31 days measured; a month needs 22. The others: 21 with under 18 hours of readings or readings that failed our checks.
Nov 202520 of 30 days measured; a month needs 21. The others: 10 with under 18 hours of readings or readings that failed our checks.
Jun 202519 of 30 days measured; a month needs 21. The others: 11 with under 18 hours of readings or readings that failed our checks.
May 202519 of 31 days measured; a month needs 22. The others: 12 with under 18 hours of readings or readings that failed our checks.
Apr 20259 of 30 days measured; a month needs 21. The others: 21 with under 18 hours of readings or readings that failed our checks.
Mar 202518 of 31 days measured; a month needs 22. The others: 13 with under 18 hours of readings or readings that failed our checks.
Feb 20258 of 28 days measured; a month needs 20. The others: 2 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.

Gangtok's worst months

MonthUS AQIDays measuredWorld rank
March 2026 8024.8 µg/m³27 of 31431stof 2,971
April 2026 7622.4 µg/m³29 of 30359thof 2,941
June 2026 6717.7 µg/m³24 of 30278thof 2,497
May 2026 6315.7 µg/m³24 of 31395thof 2,874
July 2025 5511.4 µg/m³23 of 31961stof 2,889
October 2025 529.9 µg/m³30 of 31572ndof 2,614

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.

Gangtok's worst days

DayUS AQIEpisode
21 Jan 2026 218143.0 µg/m³–
4 Apr 2025 16879.5 µg/m³Northern India, March and April 2025
3 Apr 2025 16575.5 µg/m³Northern India, March and April 2025
2 Apr 2025 16474.5 µg/m³Northern India, March and April 2025
6 Apr 2025 16473.8 µg/m³Northern India, March and April 2025
5 Apr 2025 16372.4 µg/m³Northern India, March and April 2025
29 Mar 2025 16270.9 µg/m³Northern India, March and April 2025
28 Mar 2025 16270.6 µg/m³Northern India, March and April 2025
30 Mar 2025 15967.0 µg/m³Northern India, March and April 2025
27 Mar 2025 15663.2 µg/m³Northern India, March and April 2025

Daily means, the highest since 19 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, Gangtok, India, 19 Feb 2025 – 6 Oct 2026. Monitor data from CPCB via OpenAQ; sources listed at smogrank.com/sources. smogrank.com/in/gangtok/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.

Gangtok 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).