Every site I use to check the AQI has sometimes vastly different figures…?

[mikey88]

Who do you trust…?

Some of the most prominent sites have wildly different figures…?

[Bill97]

5 minutes ago, mikey88 said:

Who do you trust…?

God

[Stocky]

Just now, mikey88 said:

Some of the most prominent sites have wildly different figures

That's because they don't all report the same way. Some give current data, some give the 24hr average. You need to check the website and see what methodology they use.

[OneMoreFarang]

As far as I know the AQI is a mix of several measurements. The measurements must all exist to give a correct value.

It seems some sites and users don't know the difference between 0 and no data. Some use 0 if no data is available.

And that obviously screws up the value of the AQI.

[cjinchiangrai]

The AQI can vary a lot over the course of the day. The government tends to report the most recent measurement but other sites may do average sampling over a period of time. You can argue over which provides the most accurate assessment. I would not want averages over more than an hour or so but the instantaneous reading can be deceptive too.

 

[KhunLA]

Have my own meter, and is usually in the same ball park as AirVisual/IQAir,  not too far off of the other/air-quality

 

https://www.iqair.com/th-en/

https://air-quality.com/?

 

Windy:

https://www.windy.com/-PM2-5-pm2p5?cams,pm2p5,2022121900,11.087,99.185,8

[mikey88]

1 hour ago, KhunLA said:

Have my own meter, and is usually in the same ball park as AirVisual/IQAir,  not too far off of the other/air-quality

 

https://www.iqair.com/th-en/

https://air-quality.com/?

 

Windy:

https://www.windy.com/-PM2-5-pm2p5?cams,pm2p5,2022121900,11.087,99.185,8

Thanks….I look at IQ Air too……for example though….at 9.20pm Dec 19……when I search AQI Chiang Mai……IQ air gives me a reading of 89………..and Accu…gives a reading of 29.

[KhunLA]

25 minutes ago, mikey88 said:

Thanks….I look at IQ Air too……for example though….at 9.20pm Dec 19……when I search AQI Chiang Mai……IQ air gives me a reading of 89………..and Accu…gives a reading of 29.

Accu is showing the PM2.5 reading

IQ is showing (prominent) AQI reading, 

Agrees with Accu with PM2.5 reading, almost