A piece of mine trivia, in deeper modern mines with forced air circulation - don’t forget adiabatic heating. As air descends, it will heat about (IIRC) 3C/5F per 1000 feet, depending on humidity. (The same effect produces warm dry chinook winds in western Canada, as the humid air rises, drops water on BC, then descends to get much warmer since it’s dry)
So deep mines will be hot for several reasons. Caves, with less force air circulation, less so.
2C/3.5F per 1000 ft is the usual number used in aviation. Not sure if the higher humidity or other factors might not be different in the context of a mine.
Nice answers. I don’t have much experience with natural caves is why. I suppose the catacombs would correspond to the “abyssal” portion of a natural cave where, beside perpetual darkness, you have constant temperature and humidity year-round, and not significantly different from a certain level at the surface.
Someone mentioned “depth” as meaning either level or vertical distance from the entrance at the surface. In both cases you will have increasing temperature in a big and complicated mine. In one adit (tunnel) the outside temperature was below 71F but quickly rose to 85F as you walked in, which was our normal main haulage temperature. The individual mine workings had temperatures anywhere from 90 to 120.