A solution to last week's Challenge can be found here!
Here's my solution. I decided to filter the data to only show the most recent year available for the selected site, and scaffolded the data to include zero rows. Colours are replicated from the AQI website. With a bit more time I'd make this into an analytic app but I'm happy with this for now.
Since Inspire 2018 is going to be in Anaheim, CA I chose the closest station located in Orange County. It was a good suggestion to make sure that the latest month is included, as the last measurements in Costa Mesa were done at the end of 2015! I didn't make an app to dynamically select the location but included the last date of measurements and played a little bit with a layout.
Edit: Here is an updated workflow & screenshots, as I didn't notice that results need to be filtered for a run month. I really need to start reading the task more carefully..