SmogRank / Taiwan / Taiwan / Erlun
Erlun, month by month
Erlun has a measured daily mean on 835 days since 8 February 2024. Its worst month was February 2026, at 83 US AQI (26.5 µg/m³), 330th of 2,866 cities on that month's world ranking. Its cleanest was July 2024, at 49 US AQI (8.9 µg/m³). 2025 averaged 69 US AQI (18.6 µg/m³), against 65 US AQI (16.4 µg/m³) in 2024.
Every month since 2024
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
5 months
| Month | Why |
|---|---|
| Nov 2025 | 12 of 30 days measured; a month needs 21. The others: 18 with under 18 hours of readings or readings that failed our checks. |
| Oct 2025 | 10 of 31 days measured; a month needs 22. The others: 21 with under 18 hours of readings or readings that failed our checks. |
| Aug 2025 | 6 of 31 days measured; a month needs 22. The others: 25 with under 18 hours of readings or readings that failed our checks. |
| Jul 2025 | No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks. |
| Feb 2024 | 6 of 29 days measured; a month needs 21. The others: 16 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.
Erlun's worst months
| Month | US AQI | World rank | Episode |
|---|---|---|---|
| February 2026 | 8326.5 µg/m³ | 330thof 2,866 | Taiwan, February 2026 |
| March 2024 | 7923.9 µg/m³ | 98thof 1,698 | Taiwan, March 2024 |
| January 2025 | 7823.5 µg/m³ | 204thof 2,474 | – |
| February 2025 | 7723.2 µg/m³ | 347thof 2,633 | Taiwan, 26 to 28 February 2025 Taiwan, 17 February 2025 |
| April 2025 | 7723.2 µg/m³ | 264thof 2,951 | – |
| January 2026 | 7622.7 µg/m³ | 314thof 2,617 | – |
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.
Erlun's worst days
| Day | US AQI | Episode |
|---|---|---|
| 27 Feb 2025 | 15055.3 µg/m³ | Taiwan, 26 to 28 February 2025 |
| 16 Mar 2024 | 13850.5 µg/m³ | Taiwan, March 2024 |
| 11 Mar 2025 | 13549.4 µg/m³ | Taiwan, March 2025 |
| 28 Feb 2025 | 12846.6 µg/m³ | Taiwan, 26 to 28 February 2025 |
| 14 Feb 2026 | 12143.6 µg/m³ | Taiwan, February 2026 |
| 17 Feb 2025 | 11842.4 µg/m³ | Taiwan, 17 February 2025 |
| 21 Feb 2026 | 11741.8 µg/m³ | – |
| 22 Feb 2026 | 11541.1 µg/m³ | – |
| 13 Feb 2026 | 11440.7 µg/m³ | Taiwan, February 2026 |
| 21 Jan 2025 | 11240.0 µg/m³ | – |
Daily means, the highest since 8 Feb 2024; 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, Erlun, Taiwan, 8 Feb 2024 – 12 Oct 2026. Monitor data from Taiwan's Ministry of Environment via OpenAQ; sources listed at smogrank.com/sources. smogrank.com/tw/erlun/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.
Erlun now: the last 24 hours, its ranks today and the last 12 months day by day.
Updated 2026-10-12 23:07 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).