This is something that has puzzled me every time I park in the underground garage under City Hall in Palo Alto. It is always so hot down there compared to the outside air.
I was about to ask if anyone knows why that is, and then realized I could search for the answer:
This reminds me of how the London Underground used to be much cooler, but the trains have raised the temperature of the clay surrounding the tunnels sufficiently that it never cools off:
This is something that has puzzled me every time I park in the underground garage under City Hall in Palo Alto. It is always so hot down there compared to the outside air.
I was about to ask if anyone knows why that is, and then realized I could search for the answer:
https://www.google.com/search?q=why+do+underground+garages+g...
Lots of interesting opinions there, including a previous HN thread.
One discussion I liked showed up when I'm signed into Google but was missing from an incognito search:
https://philip.greenspun.com/blog/2013/07/05/stupid-geophysi...