Fine particles
44.7µg/m³Moderate · 1 hourCAMS model • Open-Meteo
Yuen Long Kau HuiAir quality, PM2.5 and PM10
Check PM2.5 and PM10 particle levels alongside ozone, nitrogen dioxide and other gases. Compare the latest available concentrations with recent days and explore changes in air pollution through the available historical records.
Yuen Long Kau Hui - latest available concentrations (October 23, 2026, 09:00 local time): PM2.5: 44.7 µg/m³, PM10: 45.4 µg/m³, O₃: 56 µg/m³, NO₂: 36.4 µg/m³, SO₂: 28.2 µg/m³, CO: 660 µg/m³. These are hourly CAMS model values for a point representing the city.
Air quality questions →Yuen Long Kau Hui · Air pollutant concentrations
Data time: October 23, 2026 · 09:00 · local timeParticulate matter
45.4µg/m³Moderate · 1 hourOzone
56µg/m³Good · 1 hourNitrogen dioxide
36.4µg/m³Moderate · 1 hourSulphur dioxide
28.2µg/m³Fair · 1 hourCarbon monoxide
660µg/m³PM2.5 vs PM10 - what is the difference? → · Models and monitoring stations →
DAILY DATA · Yuen Long Kau Hui
Yuen Long Kau Hui - air pollution over recent days (2026-08-31 - 2026-10-22)
Concentrations of all available pollutants for this city.
PM2.5Lowest 18.58 2026-09-03Highest 93.16 2026-09-052026-08-31 - 2026-10-22
PM10Lowest 18.66 2026-09-03Highest 94.03 2026-09-052026-08-31 - 2026-10-22
O₃Lowest 42.83 2026-09-04Highest 94.46 2026-09-072026-08-31 - 2026-10-22
NO₂Lowest 37.79 2026-10-22Highest 94.43 2026-09-052026-08-31 - 2026-10-22
SO₂Lowest 22.2 2026-09-02Highest 76.08 2026-09-072026-08-31 - 2026-10-22
COLowest 308.29 2026-10-18Highest 931.38 2026-08-312026-08-31 - 2026-10-22
Scroll the chart or table sideways to see the full period.
| Pollutant | 2026-10-22 | 2026-10-21 | 2026-10-20 | 2026-10-19 | 2026-10-18 | 2026-10-17 | 2026-10-16 | 2026-09-07 | 2026-09-06 | 2026-09-05 | 2026-09-04 | 2026-09-03 | 2026-09-02 | 2026-09-01 | 2026-08-31 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM2.5 | 25.68 | 55.67 | 32.05 | 33.93 | 20.01 | 19.23 | 28.08 | 67.82 | 45.13 | 93.16 | 39.76 | 18.58 | 20.36 | 18.9 | 38.01 |
| PM10 | 25.83 | 56.06 | 33.18 | 34.61 | 22.83 | 23.52 | 34.48 | 68.39 | 45.67 | 94.03 | 40.09 | 18.66 | 20.47 | 19.39 | 38.18 |
| O₃ | 68.71 | 70.29 | 46.29 | 68.21 | 82.38 | 87.58 | 84.58 | 94.46 | 46.63 | 49.54 | 42.83 | 52.58 | 65.63 | 49.92 | 46.88 |
| NO₂ | 37.79 | 76.33 | 78.86 | 76.88 | 40.84 | 39.65 | 48.98 | 93.95 | 85.84 | 94.43 | 62.54 | 47.36 | 43.07 | 45.83 | 65.89 |
| SO₂ | 28.1 | 51.32 | 57.93 | 54.13 | 32.66 | 29.9 | 36.48 | 76.08 | 70.25 | 68.13 | 43.03 | 24.46 | 22.2 | 25.78 | 38.5 |
| CO | 519.67 | 869.38 | 515.79 | 555.79 | 308.29 | 337.42 | 416.08 | 688.75 | 851.42 | 810.83 | 655.96 | 526 | 474.54 | 468.92 | 931.38 |
A dot on the chart and a dash in the table indicate missing data. The latest day may be incomplete.
Air quality in nearby cities
All cities →Hong Kong · air quality in other cities
WEATHER & SURROUNDINGS
Hong Kong · weather forecast
Daily maximum and minimum temperatures. Forecast point: 22.267, 114.188. Forecast for a country reference point; conditions in the city may differ.
Scroll the forecast to see the following days.
Hong Kong · October 20, 2026: minimum temperature 25.6°C, maximum 31°C. Wind: 20.7 km/h. Humidity: 73%.
Full forecast: temperature, rainfall, wind and humidity
| Date | Day °C | Min °C | Max °C | Night °C | Rain mm | Wind m/s | Humidity % | Clouds % |
|---|---|---|---|---|---|---|---|---|
| 2026-10-20 | 29.3 | 25.6 | 31 | 26.5 | 8.7 | 5.8 | 73 | 46 |
| 2026-10-21 | 30.1 | 25.8 | 31.3 | 26.6 | 0.3 | 3.5 | 71 | 2 |
| 2026-10-22 | 27.7 | 24.5 | 31.8 | 25.5 | 0.5 | 5.9 | 60 | 46 |
| 2026-10-23 | 28.9 | 23.7 | 32.8 | 24.1 | 0.3 | 6.5 | 53 | 30 |
| 2026-10-24 | 29 | 24 | 29.6 | 28.2 | 2.1 | 8.4 | 51 | 100 |
| 2026-10-25 | 28.5 | 25.7 | 28.6 | 26.7 | 4.2 | 4.2 | 57 | 93 |
| 2026-10-26 | 27.6 | 25.2 | 27.6 | 25.3 | 0.1 | 6.9 | 60 | 3 |
| 2026-10-27 | 26.2 | 24.1 | 26.4 | 24.4 | 2.1 | 7.6 | 63 | 95 |
| 2026-10-28 | 24.2 | 23.7 | 24.3 | 24.3 | 0.5 | 9.1 | 71 | 88 |
| 2026-10-29 | 24.6 | 23.9 | 24.9 | 24.7 | 0.4 | 8.2 | 68 | 40 |
| 2026-10-30 | 25.7 | 24.4 | 25.9 | 25.3 | 0.1 | 6.9 | 70 | 16 |
| 2026-10-31 | 25.5 | 25 | 26 | 25.2 | 0.4 | 8.5 | 71 | 52 |
| 2026-11-01 | 24.9 | 24.4 | 25.4 | 25.1 | 0.2 | 8.8 | 73 | 86 |
| 2026-11-02 | 26.5 | 23.6 | 26.5 | 23.6 | 4.2 | 6 | 69 | 12 |
| 2026-11-03 | 22.8 | 21.2 | 23.9 | 23.7 | 0.1 | 6.3 | 57 | 68 |
| 2026-11-04 | 23.3 | 22 | 23.8 | 23.8 | 0.2 | 7.5 | 61 | 6 |
| 2026-11-05 | 24.3 | 23.3 | 24.6 | 24.5 | — | 9.1 | 69 | 18 |
| 2026-11-06 | 24.7 | 24 | 25.1 | 24.5 | 0.3 | 9.8 | 74 | 43 |
UV index by day · Hong Kong
Data for a country reference point. Local conditions may differ.
SPF 30-50, hat and sunglasses are a must. Better to stay in the shade 11:00-15:00.
0-2 low3-5 moderate6-7 high8-10 very high11+ extreme
Scroll the forecast to see the following days.
Hong Kong · October 22, 2026: UV index: 7.1 .
| Indicator | 2026-10-22 | 2026-10-23 | 2026-10-24 | 2026-10-25 | 2026-10-26 | 2026-10-27 | 2026-10-28 | 2026-10-29 | 2026-10-30 | 2026-10-31 | 2026-11-01 | 2026-11-02 | 2026-11-03 | 2026-11-04 | 2026-11-05 | 2026-11-06 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index | 7.1 | 7.1 | 7.1 | 7 | 6.8 | 5.6 | 5.3 | 6.8 | 6.8 | 6.6 | 2.7 | 4.3 | 5.1 | 6.4 | 3.3 | — |
Sea temperature and waves · Hong Kong
Data for a selected coastal point.
Scroll the forecast to see the following days.
Hong Kong · October 22, 2026: Sea temperature (°C): 28.6 . Wave height (m): 0.9 .
| Indicator | 2026-10-22 | 2026-10-23 | 2026-10-24 | 2026-10-25 | 2026-10-26 | 2026-10-27 | 2026-10-28 | 2026-10-29 | 2026-10-30 | 2026-10-31 | 2026-11-01 | 2026-11-02 | 2026-11-03 | 2026-11-04 | 2026-11-05 | 2026-11-06 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea temperature (°C) | 28.6 | 28.3 | 28.1 | 28.1 | 28.1 | 28.1 | 28.1 | 27.7 | 27.6 | — | — | — | — | — | — | — |
| Wave height (m) | 0.9 | 0.5 | 0.2 | 0.2 | 0.2 | 0.5 | 1.2 | 0.8 | 0.5 | — | — | — | — | — | — | — |
Sea temperature throughout the year · Hong Kong
Monthly climate values for a selected coastal area (°C).
18.4°Jan
18.8°Feb
20.5°Mar
24.1°Apr
26.7°May
28.6°Jun
29.4°Jul
28.7°Aug
28.7°Sep
27.8°Oct
24.7°Nov
21.1°Dec
| °C | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea | 18.4 | 18.8 | 20.5 | 24.1 | 26.7 | 28.6 | 29.4 | 28.7 | 28.7 | 27.8 | 24.7 | 21.1 |
AIR QUALITY QUESTIONS
Yuen Long Kau Hui · air pollution - questions and answers
What do the latest air quality data show for Yuen Long Kau Hui?
Yuen Long Kau Hui - latest available concentrations (October 23, 2026, 09:00 local time): PM2.5: 44.7 µg/m³, PM10: 45.4 µg/m³, O₃: 56 µg/m³, NO₂: 36.4 µg/m³, SO₂: 28.2 µg/m³, CO: 660 µg/m³. These are hourly CAMS model values for a point representing the city.
When was PM2.5 highest in Yuen Long Kau Hui over the past week?
The highest available daily mean PM2.5 was 55.7 µg/m³ (October 21, 2026). This comparison covers 7 days with data in the seven days before October 23, 2026. The day of the latest reading is excluded because it may be incomplete.
Is the PM2.5 concentration for Yuen Long Kau Hui an AQI score?
No. PM2.5 and PM10 are concentrations in µg/m³. AQI is a separate index calculated using a defined scale. When comparing air quality, also check other pollutants, the date and the averaging period.
What UV index does the available forecast show for Yuen Long Kau Hui?
For October 22, 2026, the forecast UV index is 7.1. The UV section also shows the following available days. The forecast is for a country reference point (Hong Kong), not the city itself.
What wind speed is forecast for Yuen Long Kau Hui?
For October 20, 2026, forecast wind speed is 20.7 km/h. The weather table includes wind, temperature and other available parameters for subsequent days. These data describe a country reference point (Hong Kong); local wind may differ.
PM2.5 · PM10 · NO₂ · O₃
Understanding air quality and pollution data
What do PM2.5 and PM10 mean?
PM2.5 and PM10 are fractions of airborne particulate matter. PM2.5 covers fine particles up to 2.5 micrometres in diameter, while PM10 covers particles up to 10 micrometres. Concentrations in µg/m³ tell you how many micrograms of particles are present in a cubic metre of air. Compare values over the same time period.
Where does the air pollution data come from?
The latest concentrations come from the CAMS atmospheric model via Open-Meteo for each city’s coordinates. Values describe a model area, so conditions on individual streets may differ. Historical monitoring station data is shown separately where available.
How does PM2.5 concentration differ from AQI?
PM2.5 is the concentration of one particle fraction, expressed in µg/m³. AQI is an index calculated using a particular scale and thresholds. The pollutant cards show concentrations. Our city ranking compares PM2.5; PM10, ozone, nitrogen dioxide and other available gases add to the picture of air quality.
Which dates do the values and charts cover?
Each current value has a data date and time. Current concentration cards show the latest available hour, daily charts summarise individual days, and monthly records let you compare longer periods. These values represent different time intervals.
How can I check pollution in my city?
Search for your city and open its air quality page. Start with PM2.5 and PM10, then check the other available pollutants and the data timestamp. Charts and tables help you compare concentrations over time. Weather and historical climate information complement the pollution data.