Just stepped outside to grab something from the car. I got in and felt that the glass roof was as hot and annoying as ever, so I grabbed an IR gun and measured its temperature. Below you have the reported temperature for the top part of the windshield and that of a spot on the roof equally close to the front crossbeam (to account for eventual heat radiating from the metal).
The app reports the car interior temperature to be 94 F and it's 84 F outside, halfway cloudy. The car had been sitting outside for a couple of hours and the AC had been running for a few seconds since it turned itself on when I unlocked the car. The sun incidence angle was more shallow for the windscreen, but I suspect that had little effect since the car's been sitting long enough to allow the windshield to collect enough energy. The temperature difference (estimated by simply touching the glass) was consistent with what I felt on every sunny day drive so far.
Windshield:
Roof:
The app reports the car interior temperature to be 94 F and it's 84 F outside, halfway cloudy. The car had been sitting outside for a couple of hours and the AC had been running for a few seconds since it turned itself on when I unlocked the car. The sun incidence angle was more shallow for the windscreen, but I suspect that had little effect since the car's been sitting long enough to allow the windshield to collect enough energy. The temperature difference (estimated by simply touching the glass) was consistent with what I felt on every sunny day drive so far.
Windshield:
Roof: