What is also REALLY missing is some variable visibility levels due to haze/fog/smog/humidity etc… for example, anyone who flew IRL in India, knows that very very rarely the visibility is over 10km.
Currently only metar data around airports adding visibility data. So if you fly over India in the sim, you can actually recognize where airports are just by seeing a dot of fog, while all the surrounding is clear to the horizon.
I am pretty sure Meteoblue has the data.