Air quality
Air quality in Santo António today
Updated
Moderate (US AQI 86) Acceptable for most people. Unusually sensitive people should consider shortening long or heavy exertion outdoors. Model estimate for Mon, Oct 26, 10:00 am (02:00 UTC).
Live AQI, PM2.5, PM10 and ozone for Santo António, Guangdong, China, with a 48-hour forecast and the best time to be outside.
- US AQI now
- 86 Moderate
- PM2.5
- 32 µg/m³ 2.1× WHO 24-h guideline
- PM10
- 33 µg/m³
- Ozone
- 63 µg/m³
- Dominant pollutant
- PM2.5 sub-index 86
- Best hour today
- 10:00 am AQI 86
- European AQI
- 50
Air quality in Santo António right now
Right now the modelled US Air Quality Index for Santo António, Guangdong, China is 86, 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 86. 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 32 µg/m³, 2.1 times the WHO 24-hour guideline of 15 µg/m³; PM10 is 33 µg/m³ against a guideline of 45; ozone is 63 µg/m³ (below the WHO 8-hour level of 100); nitrogen dioxide is 28 µg/m³ (above the 24-hour guideline of 25).
Also this hour: UV index 5.3, carbon monoxide 384 µg/m³.
Santo António AQI forecast: next 48 hours
Over the next 24 hours the AQI is forecast to range from 86 around Mon 10:00 am to 120 around Mon 8:00 pm, from "Moderate" at best to "Unhealthy for Sensitive Groups" at worst.
The following day looks similar, averaging about 104.
| Local time (Asia/Macau) | US AQI | Category | PM2.5 µg/m³ | PM10 µg/m³ | Ozone µg/m³ |
|---|---|---|---|---|---|
| Mon 10:00 am | 86 | Moderate | 31.9 | 33 | 63 |
| Mon 1:00 pm | 89 | Moderate | 34.9 | 36 | 139 |
| Mon 4:00 pm | 92 | Moderate | 39 | 40 | 182 |
| Mon 7:00 pm | 115 | Unhealthy for Sensitive Groups | 49.1 | 50 | 103 |
| Mon 10:00 pm | 99 | Moderate | 42.6 | 47 | 51 |
| Tue 1:00 am | 102 | Unhealthy for Sensitive Groups | 41.6 | 47 | 57 |
| Tue 4:00 am | 105 | Unhealthy for Sensitive Groups | 41.3 | 47 | 56 |
| Tue 7:00 am | 108 | Unhealthy for Sensitive Groups | 36.1 | 39 | 41 |
| Tue 10:00 am | 109 | Unhealthy for Sensitive Groups | 27.7 | 29 | 80 |
| Tue 1:00 pm | 107 | Unhealthy for Sensitive Groups | 28.1 | 29 | 153 |
| Tue 4:00 pm | 105 | Unhealthy for Sensitive Groups | 31.2 | 32 | 149 |
| Tue 7:00 pm | 102 | Unhealthy for Sensitive Groups | 36.6 | 38 | 78 |
| Tue 10:00 pm | 100 | Moderate | 47.1 | 53 | 68 |
| Wed 1:00 am | 103 | Unhealthy for Sensitive Groups | 49.4 | 58 | 94 |
| Wed 4:00 am | 104 | Unhealthy for Sensitive Groups | 35 | 42 | 93 |
| Wed 7:00 am | 102 | Unhealthy for Sensitive Groups | 36.8 | 40 | 71 |
| Wed 10:00 am | 103 | Unhealthy for Sensitive Groups | 32.1 | 34 | 105 |
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 Santo António today
Between 6 am and 9 pm local time, the cleanest air today is forecast around 10:00 am (AQI 86, Moderate) and the worst around 8:00 pm (AQI 120). That is a swing of 34 points, so a run or walk around 10:00 am is noticeably better.
Santo António vs the rest of China
Across 447 China cities we track, the average US AQI right now is 86 (Moderate). Santo António at 86 is about average.
It ranks 181 of 447 from cleanest to most polluted; the cleanest is Hulunbuir (19) and the most polluted Kashgar (223).
For context, the median across 3,556 cities worldwide is 58.
Air quality in cities near Santo António
| City | Distance | US AQI | Category | PM2.5 µg/m³ |
|---|---|---|---|---|
| Macau | 0 km | 76 | Moderate | 18.1 |
| Nossa Senhora de Fátima | 1 km | 76 | Moderate | 18.1 |
| Taipa | 5 km | 76 | Moderate | 18.1 |
| Zhuhai | 9 km | 76 | Moderate | 18.1 |
| Tanzhou | 10 km | 76 | Moderate | 18.1 |
| Zhongshan | 40 km | 95 | Moderate | 18.6 |
| San Tung Chung Hang | 42 km | 84 | Moderate | 17 |
| Tung Chung | 42 km | 84 | Moderate | 17 |
Model vs measured
We found no measured PM2.5 sensor cell within 25 km of Santo António, 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 49 µg/m³ in the next 24 hours while NASA satellites detected 38 fire hotspots within 300 km in the last day (nearest about 46 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 86, 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 Santo António
Air quality elsewhere
Data: Open-Meteo Air Quality API, Copernicus Atmosphere Monitoring Service (CAMS), NASA FIRMS.