First photo: Today, beautiful, clear, a pollution index of 30, “healthy”!
Second photo: Wednesday, I watched the sky get greyer and greyer as the smog rolled in. The air index level: 316, ” hazeradous” or “severe”, I’d say! We didn’t go outside on Wednesday!
Grey–a color I don’t want to see too often!!!
Smog 101: http://www.weatherland.org.hk/api.html