SmogRank / Taiwan / Taiwan / Xizhou

Xizhou, month by month

Xizhou has a measured daily mean on 835 days since 28 February 2024. Its worst month was April 2025, at 71 US AQI (19.7 µg/m³), 358th of 2,951 cities on that month's world ranking. Its cleanest was June 2025, at 33 US AQI (6.0 µg/m³). 2025 averaged 58 US AQI (12.8 µg/m³), against 55 US AQI (11.3 µg/m³) in 2024.

Every month since 2024

202558 for the year257 days measured552nd of 2,681 in the world
202455 for the year299 days measured445th of 2,097 in the world
Each square is a month's mean PM2.5 in US AQI from Xizhou'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 Xizhou 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 20256 of 31 days measured; a month needs 22. The others: 25 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 20242 of 29 days measured; a month needs 21.

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

Xizhou's worst months

MonthUS AQIDays measuredWorld rankEpisode
April 2025 7119.7 µg/m³24 of 30358thof 2,951–
April 2024 6717.6 µg/m³29 of 30306thof 2,520–
March 2024 6617.4 µg/m³27 of 31200thof 1,698–
March 2026 6315.6 µg/m³31 of 31793rdof 2,971–
April 2026 6315.5 µg/m³30 of 30552ndof 2,941–
January 2025 6315.4 µg/m³31 of 31466thof 2,474Taiwan, 21 to 22 January 2025
Taiwan, 14 to 15 January 2025

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.

Xizhou's worst days

DayUS AQIEpisode
14 Nov 2024 10336.5 µg/m³Taiwan, November 2024
11 Apr 2024 9733.9 µg/m³–
22 Jan 2025 9432.0 µg/m³Taiwan, 21 to 22 January 2025
29 Mar 2026 9130.5 µg/m³–
15 Nov 2024 9030.0 µg/m³Taiwan, November 2024
16 Apr 2025 9030.0 µg/m³–
14 Jan 2025 8829.1 µg/m³Taiwan, 14 to 15 January 2025
4 Mar 2024 8828.9 µg/m³–
12 Apr 2024 8828.9 µg/m³–
4 Apr 2025 8828.7 µg/m³–

Daily means, the highest since 28 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, Xizhou, Taiwan, 28 Feb 2024 – 12 Oct 2026. Monitor data from Taiwan's Ministry of Environment via OpenAQ; sources listed at smogrank.com/sources. smogrank.com/tw/xizhou/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.

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

Updated 2026-10-12 21:07 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).