[rkapsoro]

Yeah, I've noticed this too.

It looks like the air quality models that iOS Weather is using are integrated into a single system, and then that system is asked to render maps in any of the different regions' AQI systems.

Which means, as OP has observed, if you open the map from one region, and then navigate the map viewer to another region, you can see how the AQI scoring system from the first region would evaluate the second. Which is rather interesting.

Also fwiw I've reckoned that these AQI models are clearly highly algorithmic, extrapolating and synthesizing data where sensors are not available.