Air quality
Air quality in Tin Shui Wai today
Updated
Moderate (US AQI 87) Acceptable for most people. Unusually sensitive people should consider shortening long or heavy exertion outdoors. Model estimate for Mon, Oct 26, 8:00 am (00:00 UTC).
Live AQI, PM2.5, PM10 and ozone for Tin Shui Wai, Yuen Long, Hong Kong, with a 48-hour forecast and the best time to be outside.
- US AQI now
- 87 Moderate
- PM2.5
- 35 µg/m³ 2.4× WHO 24-h guideline
- PM10
- 36 µg/m³
- Ozone
- 27 µg/m³
- Dominant pollutant
- PM2.5 sub-index 87
- Best hour today
- 8:00 am AQI 87
- European AQI
- 52
Air quality in Tin Shui Wai right now
Right now the modelled US Air Quality Index for Tin Shui Wai, Yuen Long, Hong Kong is 87, which falls in the "Moderate" band (up to 100). Acceptable for most people. Unusually sensitive people should consider shortening long or heavy exertion outdoors.
The index is driven mainly by PM2.5, whose own sub-index is 87. Fine and coarse particles come from traffic, heating, industry, dust and smoke; they build up on calm nights and clear when wind or rain arrives.
PM2.5 is 35 µg/m³, 2.4 times the WHO 24-hour guideline of 15 µg/m³; PM10 is 36 µg/m³ against a guideline of 45; ozone is 27 µg/m³ (below the WHO 8-hour level of 100); nitrogen dioxide is 37 µg/m³ (above the 24-hour guideline of 25).
Also this hour: UV index 1.2, carbon monoxide 569 µg/m³.
Tin Shui Wai AQI forecast: next 48 hours
Over the next 24 hours the AQI is forecast to range from 87 around Mon 8:00 am to 94 around Tue 7:00 am, staying "Moderate" throughout.
The following day looks similar, averaging about 95.
| Local time (Asia/Hong_Kong) | US AQI | Category | PM2.5 µg/m³ | PM10 µg/m³ | Ozone µg/m³ |
|---|---|---|---|---|---|
| Mon 8:00 am | 87 | Moderate | 35.4 | 36 | 27 |
| Mon 11:00 am | 89 | Moderate | 27.4 | 28 | 95 |
| Mon 2:00 pm | 90 | Moderate | 26 | 26 | 128 |
| Mon 5:00 pm | 91 | Moderate | 27.8 | 28 | 110 |
| Mon 8:00 pm | 92 | Moderate | 35.3 | 38 | 45 |
| Mon 11:00 pm | 91 | Moderate | 37 | 42 | 48 |
| Tue 2:00 am | 92 | Moderate | 35.2 | 40 | 59 |
| Tue 5:00 am | 93 | Moderate | 33.3 | 37 | 44 |
| Tue 8:00 am | 94 | Moderate | 34 | 36 | 40 |
| Tue 11:00 am | 93 | Moderate | 25.9 | 27 | 116 |
| Tue 2:00 pm | 93 | Moderate | 27.5 | 29 | 143 |
| Tue 5:00 pm | 94 | Moderate | 30.9 | 32 | 115 |
| Tue 8:00 pm | 94 | Moderate | 42.6 | 46 | 72 |
| Tue 11:00 pm | 97 | Moderate | 44.1 | 51 | 95 |
| Wed 2:00 am | 98 | Moderate | 32.6 | 40 | 117 |
| Wed 5:00 am | 96 | Moderate | 22.8 | 26 | 95 |
| Wed 8:00 am | 94 | Moderate | 29 | 30 | 77 |
Every third hour of the CAMS forecast via Open-Meteo. US AQI uses rolling averages (24 h for particles, 8 h for ozone), so it moves more slowly than the hourly concentrations.
Best time to be outside in Tin Shui Wai today
Between 6 am and 9 pm local time, the cleanest air today is forecast around 8:00 am (AQI 87, Moderate) and the worst around 7:00 pm (AQI 92). The difference across the day is small, so timing matters little.
Tin Shui Wai vs the rest of Hong Kong
Across 23 Hong Kong cities we track, the average US AQI right now is 85 (Moderate). Tin Shui Wai at 87 is about average.
It ranks 11 of 23 from cleanest to most polluted; the cleanest is Hong Kong (85) and the most polluted Jordan (85).
For context, the median across 3,909 cities worldwide is 57.
Air quality in cities near Tin Shui Wai
| City | Distance | US AQI | Category | PM2.5 µg/m³ |
|---|---|---|---|---|
| Yuen Long | 3 km | 85 | Moderate | 22.4 |
| Yuen Long Kau Hui | 3 km | 85 | Moderate | 22.4 |
| Yuen Long San Hui | 4 km | 85 | Moderate | 22.4 |
| Tuen Mun | 8 km | 85 | Moderate | 22.4 |
| Shenzhen | 12 km | 85 | Moderate | 22.4 |
| Fanling | 15 km | 85 | Moderate | 22.4 |
| Tsuen Wan | 15 km | 85 | Moderate | 22.4 |
| Tsing Yi Town | 16 km | 85 | Moderate | 22.4 |
Model vs measured
We found no measured PM2.5 sensor cell within 25 km of Tin Shui Wai, so the numbers on this page are model estimates. Models capture regional pollution well but can miss very local sources such as a busy road or a nearby fire.
Wildfire smoke
PM2.5 is forecast to reach 39 µg/m³ in the next 24 hours while NASA satellites detected 33 fire hotspots within 300 km in the last day (nearest about 2 km away). Smoke is a likely contributor: keep windows closed, run an air purifier or HVAC filter, and check the fire map before heading out.
Advice for sensitive groups
At 87, most people are fine outdoors. If you are unusually sensitive to PM2.5, keep long or intense workouts to the cleaner hours shown above.
What the US AQI numbers mean
| US AQI | Category | What it means |
|---|---|---|
| 0-50 | Good | Air quality is satisfactory and poses little or no risk; a good time for outdoor activity. |
| 51-100 | Moderate | Acceptable for most people. Unusually sensitive people should consider shortening long or heavy exertion outdoors. |
| 101-150 | Unhealthy for Sensitive Groups | People with heart or lung disease, older adults, children and teens should cut back on prolonged or heavy exertion outdoors. |
| 151-200 | Unhealthy | Everyone should reduce prolonged or heavy exertion outdoors; sensitive groups should avoid it and keep windows closed. |
| 201-300 | Very Unhealthy | Health alert: everyone should avoid prolonged or heavy exertion outdoors, and sensitive groups should stay indoors. |
| 301-500 | Hazardous | Emergency conditions: everyone should avoid all outdoor physical activity and stay indoors with filtered air if possible. The scale tops out at 500; heavier dust or smoke is shown as 500. |
Values on this page are modelled by CAMS (Copernicus) and served by Open-Meteo; they are estimates for the area around the city centre, not readings from an official monitor.
Nearby cities
More for Tin Shui Wai
Air quality elsewhere
Data: Open-Meteo Air Quality API, Copernicus Atmosphere Monitoring Service (CAMS), NASA FIRMS.