Hedley Environmental Index Summary

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.



27 Sep 2021, 11:00:00

Band HEI Station
low 1-3
moderate 4-6
high 7-9
very high 10-12
serious 12+
not available NA