Can't see very far outside this morning.
Seems like a big difference between the Government's data on aqhi.gov.hk and the data on aqicn.org.
For example, let's take the numbers for Central/Western at 6am this morning:
Date Time NO2 O3 SO2 CO PM10 PM2.5 2019-01-12 06:00 110.0 0.6 12.0 - 79.9 59.9
AQICN has PM2.5 maxed out in the reds around ~150 while the government's AQHI only has it at 59.9 (with an orange color label on their map) but the gov's AQHI has a higher reading for PM10.
Whose numbers are correct? Did somebody not calibrate their machines properly?
(...alternatively just ignore both websites and wear a mask)