SmogRank / Taiwan / Taipei / Sanzhi

Sanzhi, month by month

Sanzhi has a measured daily mean on 825 days since 8 February 2024. Its worst month was April 2024, at 60 US AQI (13.9 µg/m³), 494th of 2,520 cities on that month's world ranking. Its cleanest was October 2024, at 14 US AQI (2.6 µg/m³).

Every month since 2024

2025too few days for a mean (a year needs 256)251 days measured
202438 for the year295 days measured1,544th of 2,097 in the world
Each square is a month's mean PM2.5 in US AQI from Sanzhi'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 Sanzhi marked; each year, the year's. A dashed square is the running month, so far.
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

5 months
MonthWhy
Nov 202512 of 30 days measured; a month needs 21. The others: 18 with under 18 hours of readings or readings that failed our checks.
Oct 202510 of 31 days measured; a month needs 22. The others: 21 with under 18 hours of readings or readings that failed our checks.
Aug 20252 of 31 days measured; a month needs 22. The others: 29 with under 18 hours of readings or readings that failed our checks.
Jul 2025No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Feb 20246 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.

Sanzhi's worst months

MonthUS AQIDays measuredWorld rank
April 2024 6013.9 µg/m³28 of 30494thof 2,520
April 2025 5913.5 µg/m³24 of 30624thof 2,951
March 2024 5712.5 µg/m³27 of 31247thof 1,698
April 2026 5410.5 µg/m³30 of 30857thof 2,941
March 2025 529.8 µg/m³30 of 311,625thof 2,862
May 2025 498.9 µg/m³24 of 311,122ndof 2,826

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.

Sanzhi's worst days

DayUS AQIEpisode
17 Feb 2025 9633.3 µg/m³Taiwan, 17 February 2025
3 Apr 2024 8628.0 µg/m³–
12 Apr 2024 8426.9 µg/m³–
8 Mar 2024 8225.9 µg/m³–
11 Apr 2024 8125.0 µg/m³–
21 Jan 2025 7924.2 µg/m³–
28 Nov 2025 7924.2 µg/m³–
22 Apr 2024 7823.5 µg/m³–
16 Apr 2025 7723.3 µg/m³–
7 Jan 2026 7723.3 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, Sanzhi, 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/sanzhi/history (accessed 13 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.

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

Updated 2026-10-13 01:07 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).