Out of the weather
Indoor pickleball courts
Pickleball Court Hub marks a court indoor only when at least two sources agree. Google has no indoor field, so a name with the word gym is not enough. Mixed means the sources agreed the place is both indoor and outdoor. This page links the states and cities where that bar has been cleared.
Right now that is 1 confirmed indoor court and 1 confirmed as both indoor and outdoor. Counts move only when a new court passes the same check.
Indoor pickleball by state
Cities
The full rule is on the methodology page.