On my 4070, it is under GPU Memory Junction Temperature in Hwinfo64, same for my 9070. I still have to decide if i keep it, it's a Powercolor Reaper 9070.
The GPU and GPU hot spot temps are great, but the vRAM goes to about 92ºC with 24ºC ambient. That means that in a few months it will go to about 100ºC since i have around 30-32ºC in my room in the summer months.
Now, *tin foil alert !

My 4070(Asus Dual) and my 9070 both draw about 200W, the 4070 is about 950 grams the 9070 is 860 grams. The Nvidia card is 10º hotter on the GPU core, but 10º cooler on the vRAM. How ?
The AMD card has PTM but no way that accounts to -10º while having the memory 10º hotter.
So, maybe AMD is under reporting the GPU temperature ? like on the first gen Ryzen there were two temperature readings for the CPU.
This are the two cards head-to-head
Something really is amiss here. Another post related to my Hellhound 7800 XT's low temperatures:
Solid front panel.
No doubt BoggledBeagle's conditions are better, but 17°C better? I doubt it.
I've seen differences in the 10-20c range solely due to case so it's still possible, he mentioned 20c ambient so let's say 4-5c from ambient and 10c from case and that's pretty much 17c with some margin of error
If 4090 can't be compared for whatever reason (cooler is actually 74 mm compared to 70 mm, not much difference), then how did PowerColor Hellhound 7800 XT had 62°C at 265W and 1165 rpm? That's 14°C less than 5070 Ti.
GPU thickness doesn't say much, and even with the same...
Today I tested my RTX 4070 SUPER ASUS TUF Gaming OC and RX 9070 Gigabyte Gaming OC.
RTX 4070 SUPER ASUS TUF Gaming OC (1177 g) - 240W, 1500 rpm, room temperature 25°C - 81°C, Hot Spot 104°C, Memory 94°C
RX 9070 Gigabyte Gaming OC (1117 g) - 245W, 1500 rpm, room temperature 26°C - 64°C, Hot Spot 81°C, Memory 94°C
RTX 5070 Ti Gigabyte Gaming OC (1768 g) - 250W, 1500 rpm, room temperature 24°C - 67°C, Memory 76°C
RTX 3060 Ti Gigabyte Aorus Elite (1040 g) - 240W, 1500 rpm (it was beginning of December 2021, so I think 23°C in room) - 68°C, Hot Spot 78°C
It's just not possible for AMD to have 3°C less with 650 g lighter cooler (actually whole card, but we can simplify) and 17°C less with 60 g lighter cooler.
But if I look at my old Aorus Elite, it was Nvidia, and also as cold as an air cooled card can be, especially considering it weighed 1 kg and not 2 kg.
So looking at my 3060 Ti and 9070 temperatures, they seem to add up.
But for now, I can only say safest bet is to buy a 2 kg card if you want a cool card. Even 5070 Ti Gigabyte Gaming OC does not weigh as much and outside dimensions are the same as on 5080 and 5090.
My previous Palit 4080 and Gigabyte Gaming OC 4090 had 2 kg and they were cooler than 5070 Ti.