SmogRank / Hong Kong / Yuen Long / Tin Shui Wai
Tin Shui Wai, month by month
Tin Shui Wai has a measured daily mean on 1,115 days since 1 January 2023. Its worst month was December 2024, at 99 US AQI (34.6 µg/m³), 63rd of 2,616 cities on that month's world ranking. Its cleanest was June 2025, at 35 US AQI (6.3 µg/m³). 2025 averaged 65 US AQI (16.6 µg/m³), against 66 US AQI (17.2 µg/m³) in 2024.
Every month since 2023
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
11 months
| Month | Why |
|---|---|
| Jul 2026 | 2 of 31 days measured; a month needs 22. The others: 29 with under 18 hours of readings or readings that failed our checks. |
| Jun 2026 | No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks. |
| May 2024 | 18 of 31 days measured; a month needs 22. The others: 13 with under 18 hours of readings or readings that failed our checks. |
| Mar 2024 | 18 of 31 days measured; a month needs 22. The others: 13 with under 18 hours of readings or readings that failed our checks. |
| Oct 2023 | 18 of 31 days measured; a month needs 22. The others: 13 with under 18 hours of readings or readings that failed our checks. |
| Jul 2023 | 18 of 31 days measured; a month needs 22. The others: 1 missing from OpenAQ's archive, 12 with under 18 hours of readings or readings that failed our checks. |
| Jun 2023 | 15 of 30 days measured; a month needs 21. The others: 15 with under 18 hours of readings or readings that failed our checks. |
| May 2023 | 16 of 31 days measured; a month needs 22. The others: 15 with under 18 hours of readings or readings that failed our checks. |
| Apr 2023 | 18 of 30 days measured; a month needs 21. The others: 2 missing from OpenAQ's archive, 10 with under 18 hours of readings or readings that failed our checks. |
| Mar 2023 | 8 of 31 days measured; a month needs 22. The others: 19 missing from OpenAQ's archive, 4 with under 18 hours of readings or readings that failed our checks. |
| Feb 2023 | 1 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.
Tin Shui Wai's worst months
| Month | US AQI | World rank |
|---|---|---|
| December 2024 | 9934.6 µg/m³ | 63rdof 2,616 |
| December 2025 | 9030.2 µg/m³ | 309thof 3,006 |
| January 2026 | 8829.0 µg/m³ | 187thof 2,617 |
| January 2025 | 8527.6 µg/m³ | 123rdof 2,474 |
| January 2023 | 8426.6 µg/m³ | 84thof 1,261 |
| January 2024 | 8326.4 µg/m³ | 157thof 2,385 |
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.
Tin Shui Wai's worst days
| Day | US AQI |
|---|---|
| 13 Apr 2025 | 15764.5 µg/m³ |
| 14 Apr 2025 | 15662.2 µg/m³ |
| 30 Dec 2025 | 15460.1 µg/m³ |
| 31 Dec 2023 | 15257.0 µg/m³ |
| 30 Dec 2024 | 15256.3 µg/m³ |
| 29 Dec 2024 | 15156.0 µg/m³ |
| 13 Jan 2026 | 14653.6 µg/m³ |
| 24 Jan 2026 | 14051.4 µg/m³ |
| 27 Jan 2026 | 13549.3 µg/m³ |
| 31 Dec 2024 | 13449.0 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, Tin Shui Wai, 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/tin-shui-wai/history (accessed 13 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.
Tin Shui Wai now: the last 24 hours, its ranks today and the last 12 months day by day.
Updated 2026-10-13 00:07 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).