Hedley Environmental Index (HEI) is calculated based on five criteria pollutants with reference to World Health Organization Air Quality Guideline. The HEI is the real-time median of all urban rooftop stations.
For more details, please refer to FAQ.
06 Mar 2021, 21:00:00
Band | HEI | Station |
low | 1-3 | |
moderate | 4-6 | |
high | 7-9 | |
very high | 10-12 |
|
serious | 12+ |
|
not available | NA |
|