SmogRank / Hong Kong / Kwai Tsing District / Kwai Chung

Kwai Chung, month by month

Kwai Chung has a measured daily mean on 1,136 days since 1 January 2023. Its worst month was December 2024, at 90 US AQI (30.3 µg/m³), 91st of 2,616 cities on that month's world ranking. Its cleanest was July 2024, at 35 US AQI (6.3 µg/m³). 2025 averaged 63 US AQI (15.4 µg/m³), against 63 US AQI (15.3 µg/m³) in 2024.

Every month since 2023

202664 so far216 days measured492nd of 2,793 in the world
2023too few days for a mean (a year needs 256)232 days measured
Jan77#112Feb1 dayMar9 daysApr19 daysMay16 daysJun15 daysJul19 daysAug53#623Sep52#666Oct18 daysNov67#105Dec74#143
Each square is a month's mean PM2.5 in US AQI from Kwai Chung'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 Kwai Chung 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

10 months
MonthWhy
Jul 20262 of 31 days measured; a month needs 22. The others: 29 with under 18 hours of readings or readings that failed our checks.
Jun 2026No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks.
Mar 202419 of 31 days measured; a month needs 22. The others: 12 with under 18 hours of readings or readings that failed our checks.
Oct 202318 of 31 days measured; a month needs 22. The others: 13 with under 18 hours of readings or readings that failed our checks.
Jul 202319 of 31 days measured; a month needs 22. The others: 1 missing from OpenAQ's archive, 11 with under 18 hours of readings or readings that failed our checks.
Jun 202315 of 30 days measured; a month needs 21. The others: 15 with under 18 hours of readings or readings that failed our checks.
May 202316 of 31 days measured; a month needs 22. The others: 15 with under 18 hours of readings or readings that failed our checks.
Apr 202319 of 30 days measured; a month needs 21. The others: 2 missing from OpenAQ's archive, 9 with under 18 hours of readings or readings that failed our checks.
Mar 20239 of 31 days measured; a month needs 22. The others: 19 missing from OpenAQ's archive, 3 with under 18 hours of readings or readings that failed our checks.
Feb 20231 of 28 days measured; a month needs 20. The others: 25 missing from OpenAQ's archive, 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.

Kwai Chung's worst months

MonthUS AQIDays measuredWorld rank
December 2024 9030.3 µg/m³31 of 3191stof 2,616
December 2025 8024.6 µg/m³30 of 31374thof 3,006
January 2025 8024.5 µg/m³30 of 31181stof 2,474
January 2026 7823.8 µg/m³31 of 31281stof 2,617
January 2023 7722.8 µg/m³23 of 31112thof 1,261
December 2023 7421.2 µg/m³29 of 31143rdof 2,247

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.

Kwai Chung's worst days

DayUS AQI
14 Apr 2025 15966.3 µg/m³
13 Apr 2025 15358.7 µg/m³
30 Dec 2025 14151.9 µg/m³
16 Feb 2025 13649.8 µg/m³
29 Dec 2024 13448.7 µg/m³
13 Jan 2026 13047.4 µg/m³
31 Dec 2023 12946.7 µg/m³
30 Dec 2024 12645.6 µg/m³
28 Dec 2024 12545.4 µg/m³
24 Jan 2026 12545.4 µg/m³

Daily means, the highest since 1 Jan 2023; 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, Kwai Chung, Hong Kong, 1 Jan 2023 – 12 Oct 2026. Monitor data from Hong Kong's Environmental Protection Department via OpenAQ; sources listed at smogrank.com/sources. smogrank.com/hk/kwai-chung/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.

Kwai Chung 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).