Bighorn
Top Supercharger
I also appreciated the shade in El Centro, where the Superchargers are located on the third level of a shopping mall parking structure. Hard to find unless you know where to look, though.
I think you're thinking of Temecula. I've forgotten tons of details about SC stops, but searching for the chargers in that indoor garage is burned into my memory
El Centro was 106F with no shade, IIRC--pretty much the same as all the southwest chargers that day.
Keep at it!