Air quality
Air quality in Chang-hua today
Updated
Moderate (US AQI 67) 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 Chang-hua, Taiwan, Taiwan, with a 48-hour forecast and the best time to be outside.
- US AQI now
- 67 Moderate
- PM2.5
- 22 µg/m³ 1.5× WHO 24-h guideline
- PM10
- 25 µg/m³
- Ozone
- 46 µg/m³
- Dominant pollutant
- PM2.5 sub-index 67
- Best hour today
- 8:00 am AQI 67
- European AQI
- 44
Air quality in Chang-hua right now
Right now the modelled US Air Quality Index for Chang-hua, Taiwan, Taiwan is 67, 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 67. 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 22 µg/m³, 1.5 times the WHO 24-hour guideline of 15 µg/m³; PM10 is 25 µg/m³ against a guideline of 45; ozone is 46 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 1.8, carbon monoxide 347 µg/m³.
Chang-hua AQI forecast: next 48 hours
Over the next 24 hours the AQI is forecast to range from 67 around Mon 8:00 am to 85 around Tue 5:00 am, staying "Moderate" throughout.
The following day is expected to be worse, averaging about 86 against 78 for the next 24 hours.
| Local time (Asia/Taipei) | US AQI | Category | PM2.5 µg/m³ | PM10 µg/m³ | Ozone µg/m³ |
|---|---|---|---|---|---|
| Mon 8:00 am | 67 | Moderate | 21.8 | 25 | 46 |
| Mon 11:00 am | 69 | Moderate | 24.4 | 30 | 82 |
| Mon 2:00 pm | 73 | Moderate | 33.3 | 42 | 117 |
| Mon 5:00 pm | 77 | Moderate | 31.2 | 40 | 102 |
| Mon 8:00 pm | 80 | Moderate | 27.9 | 34 | 67 |
| Mon 11:00 pm | 82 | Moderate | 28.2 | 33 | 50 |
| Tue 2:00 am | 84 | Moderate | 27 | 32 | 55 |
| Tue 5:00 am | 85 | Moderate | 25.8 | 32 | 55 |
| Tue 8:00 am | 85 | Moderate | 26.7 | 33 | 55 |
| Tue 11:00 am | 86 | Moderate | 29.3 | 38 | 82 |
| Tue 2:00 pm | 87 | Moderate | 31.1 | 41 | 128 |
| Tue 5:00 pm | 86 | Moderate | 24.9 | 34 | 103 |
| Tue 8:00 pm | 85 | Moderate | 29.5 | 39 | 63 |
| Tue 11:00 pm | 86 | Moderate | 31.4 | 39 | 53 |
| Wed 2:00 am | 86 | Moderate | 24.2 | 29 | 45 |
| Wed 5:00 am | 85 | Moderate | 19 | 22 | 42 |
| Wed 8:00 am | 83 | Moderate | 19.8 | 25 | 52 |
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 Chang-hua today
Between 6 am and 9 pm local time, the cleanest air today is forecast around 8:00 am (AQI 67, Moderate) and the worst around 9:00 pm (AQI 81). That is a swing of 14 points, so a run or walk around 8:00 am is noticeably better.
Chang-hua vs the rest of Taiwan
Across 18 Taiwan cities we track, the average US AQI right now is 73 (Moderate). Chang-hua at 67 is 6 points cleaner than average.
For context, the median across 3,556 cities worldwide is 58.
Air quality in cities near Chang-hua
| City | Distance | US AQI | Category | PM2.5 µg/m³ |
|---|---|---|---|---|
| Taichung | 15 km | 81 | Moderate | 22.8 |
| Toufen | 77 km | 60 | Moderate | 23.1 |
| Hsinchu | 91 km | 60 | Moderate | 23.1 |
| Zhubei | 96 km | 60 | Moderate | 23.1 |
| Bade | 120 km | 60 | Moderate | 18.5 |
| Yongkang | 121 km | 108 | Unhealthy for Sensitive Groups | 26.9 |
| Neili | 122 km | 60 | Moderate | 18.5 |
| Tainan | 126 km | 108 | Unhealthy for Sensitive Groups | 26.9 |
Model vs measured
We found no measured PM2.5 sensor cell within 25 km of Chang-hua, 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.
Advice for sensitive groups
At 67, 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 Chang-hua
Air quality elsewhere
Data: Open-Meteo Air Quality API, Copernicus Atmosphere Monitoring Service (CAMS).