The last time I presented daily API data was on August 24th, the final day of the Olympics. With the Paralympics now underway, I figure it's time to take another detailed look at the air quality status.
Since 7/20, the day the odd/even car ban and other temporary air quality control policies went into effect, the graph of daily API values is as follows:
A couple of things worth noting:
1) Though the API was below the target cut-off of 100 for the entire Olympic period, between the Olympics and Paralympics we saw one day, 8/29, in which the API shot up to 110.
2) The API data for 9/6 is conspicuously missing. (As always, my source for API data is the query at the bottom of MEP's air quality page.) Does anyone out there have this data point, perhaps from the Beijing EPB? I seem to remember that day - the day of the Paralympic opening ceremony - being particularly hazy, but I didn't check the data then. Missing data is always concerning, of course, but especially here.
Still, though, the results for overall air quality since 7/20 are remarkable. The average API from 7/20-9/9 of this year is 63; during the same period last year the average was 89.
Lastly, the weather has seemed quite strange recently here in Beijing; over the last few days I've seen two of the heaviest thunderstorms I can remember in China. Anyone agree?