Assume you like https://www.airvisual.com/earth or https://www.airvisual.com/air-quality-map but your city/country is not yet on the map. Or you already have Node but missing outdoor air quality measurements. There is a way to fix it. You can install and register your AirVisual node outdoor. Yes, it needs yet another node to be bought. Article on AirVisual site about sharing your data : http://support.airvisual.com/knowledgebase/articles/948895-how-can-i-make-my-outdoor-node-pro-s-data-public
And below is example of
AirVisual node itself is absolutely indoor device. It needs good weather proof case that is also have good airflow.
It just a test. Not a case really. Not an outdoor. 
So, let's measure and buy something that might be used as an outdoor case.
Do It Yourself outdoor case for AirVisual Node using plastic air vent grilles and plastic flower pots. Some cuts and glue
Those outdoor installation was successfully registered and used for 1.5 years.
Strong magnet mount, new wire and USB socket on the case. Old USB extension cable was still working, but looks oxidized. So to ensure operation for some couple of more years..
Yes, buying two AirVisual nodes is expensive. And Yes, creating that kind of case, mounting, setup/register as outdoor takes a lot of hours.