06:00, over 150: i.imgur.com/bC2yJ76.png

Trucks rumbling around the streets, kicking up dust and spewing diesel into the air...

The air was pretty bad all day yesterday. I have been comparing Kunming with Shanghai downtown (not industrial area) for over a month now. When Kunming is at its lowest they are pretty much the same on many days. Only about 10 points in it. However, when Kunming peaks, it is significantly worse than Shanghai. Like now.
There was an improvement when we had all that rain a week or so ago, but it seems to have slipped back up.
I don't think it is that much to do with construction, although it is a factor. The really heavy trucks, most with worn out or old tech engines, are kept out of the city during the day. The arterial routes are full of these trucks after about 9pm, through till about 7am. You can see how much pollution they generate. If you drive along these roads, at these times, the air is very murky.
8.14 am Shanghai 72 (downtown 74-91), Kunming 149 (downtown 152-163).

I cycled on the 3rd east ring road around 11pm the other night and it was almost impossible to see the road and the big speeding trucks with all the dust blocking the view.

When you look at that graph, and, indeed, today's, you'll notice that the peak moments coincide with low wind speeds. Winds are very strong in spring afternoons and I believe they blow a lot of the pollution away. When the wind dies down at night, the air fills up with pollution again. From diesel trucks, certainly, but construction, too. And agricultural stalk burning.

What puzzles me is that the humidity, which reaches 100% at night, doesn't precipitate the pollution. I thought it should?

Anyway, high AQI rates are common for Kunming in spring. But that doesn't mean it isn't utterly disgusting. We should all be aware that we're slowly being killed here.

That said, on average Kunming is about as bad Charleroi, a city just 70 km south of Brussels. Brussels isn't that great either, struggling between Moderate and Unhealthy for sensitive groups.

Perhaps because the last few days have been windy? Also - the city's cleaning up to prepare for the south asia expo - so lots of cleaning up things to do - finishing off construction, replacing sidewalks, etc...and the gusting winds didn't help matters.

It is interesting to see the map for Dortmund, Bochum, and Essen in Germany's industrial heartland. All green flags. Very few yellows across Germany and only one orange. Considering Germany is still a major manufacturing economy, and many said that too much regulation would not be affordable by industry.

Germany does have very strong environmental protection regulations. They seem to be working. Especially if you compare it to Germany's neighbours, who also have regulation. Others are still much cleaner than Asian counterparts.

NB It is the middle of the night there now. It will be interesting to see how it is in about 7-8 hours.

I don't trust the dongfeng aqi reading for now. It's getting some nearby source skewing it. It's was way off compared to the other 4. Then recently it went back to reading 20 or so above the other 4. Now it's back to double again. On the other hand, the other 4 meters seem to read in tandem; all green, all yellow, or all red. Luckily, I can confirm the aqi by looking out my window since I have a large view of Kunming's westside. I find the other 4 give a pretty good indication of air quality for the day.

As to the 6am reading, that is construction vehicles. The trucks roll nonstop all night till before the buses start. Their emission pollution is easily 200-500x per auto. They drive around emitting dust. They kick it up also. Noisy too.

dongfang probably correct reading. yes local source but that is real polution. could have gone down over qingming with less people working.it is probably getting all the crap from the erhuan nan/dong lu interchange and traffic pouring off between there and station, and all that traffic coming up from yuxi and to from guandu, etc. and traffic jams on that section as wind is from south and it is south of dongfanglu. me i trust the readings. a lot of those truchs are not construction but heading in and out of the logistics places and big markets. i see big pipes and other industrial crap being carried up and down, much more than construction crap. the 40 footer trusck are not construction