I had a HKG layover a couple weeks ago with a subsequent daylight departure for Almaty. The weather was clear, well it wasn't cloudy The pollution in HKG seems to me, looking out from the gym at the Sheraton Hotel, as worse than I ever remember. The hills look blue, the sky a dull gray.
In departing HKG for ALA, we fly North from HKG than bare West, a good view out the left side of the Pearl delta, with the cites of Shenzhen and Guangzhou easily in sight. Again, a nice day (by Chinese standards) no obvious clouds but a haze so thick around a mass of humanity that was both aught inspiring and sad. This part of China is in the grip of a sea of pollution that will create problems worldwide, let along within their own country or over the mountains in HKG. Good luck to those of you moving into this cesspool, I hope you have a strong respiratory system, you going to need it.