It's Official: Hourly PM2.5 Reports in Beijing

In what I think is the biggest public health advancement in China during my five years here, the Beijing Municipal Environmental Monitoring Center (BJMEMC) has just started to publish hourly PM2.5 readings on their website at You can access the numbers there, and then click on the PM2.5 tag.

It’s truly an amazing step, and I hope it gets even better over the next few months. I’d like to see a couple improvements:

  • Correction, Feb 3: this reading is actually one monitor, on the western side of the city, and not a city-wide average, as I had incorrectly stated before. I’m told that other PM2.5 monitors will be added as the year progresses. Right now the PM2.5 data is a city-wide average. I’d prefer to see hourly updates from each of their monitors. As you can see from their PM10 data, the readings vary widely between city districts and between rural and urban monitors.
  • I’d also like an archived database to access previous results
  • There is no AQI posted for each PM2.5 number, which decreases its real-world usefulness. You have to convert yourself (just multiply the PM2.5 reading by 1,000 and use this online calculator)

How Does It Compare?

One obvious question is: how do the numbers compare to the US Embassy’s famous Beijing monitor? I’ve checked a couple times and found the numbers relatively the same:

  • January 26 morning (10 readings): US Embassy is 73 ug/m3 (= AQI 155) and BJMEMC is 80 ug/m3 (= AQI 159)
  • January 27 morning (10 readings): US Embassy is 93 ug/m3 (= AQI 167) and BJMEMC is 72 ug/m3 (= AQI 155)

It’s only a couple readings so far, but those AQI differences are surprisingly and reassuringly similar.

Now What?

I really give credit to the BJMEMC for pushing this data many years ahead of schedule. It’s a very positive step which should be acknowledged. China is now ahead of many developing countries, which mostly publish only PM10 data. So now that there is official data, what’s next?

  • Will the US Embassy shut down their site, since it technically is no longer needed?
  • Will local schools start having air pollution action plans?
  • Will such data actually quicken public efforts to clean the air?

Stay tuned…

PM2.5 Beijing Air Pollution Monitor
PM2.5 Beijing Air Pollution Monitor

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One thought on “It's Official: Hourly PM2.5 Reports in Beijing”

  1. Good news to hear. I hope, though, that the embassy continues releasing their data, even if BJMEMC gets a sensor in that area. Their data, along with other independent sources, could provide some useful validation of official numbers.

    As for the claims that the embassy’s measurements are distorted because of the location: does close proximity to roads and construction distort the picture or bring it closer to people’s actual experiences?

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