Roughly, a cave's temperature is the yearly average surface temperature of that area. Exceptions: some caves have areas that trap cold winter air and hold that colder temperature into late spring or even summer. Some caves are heated by hot springs.
There isn't a "The temperature". It will depend on the cave and its location for a start.
In caves taking rivers it will be a function of the mean temperature of the surface water the cave is absorbing, and of the air above the water in the cave.
In caves entirely drowned such as those of the Floridan and Bahamanian 'Blue Holes' it will be a function of the mean temperatures of both the sea and the input fresh water.
a cave that is underwater in freshwater
A cave that is underwater..? It's a cave that lies underneath a body of water.
underwater cave
The underwater cave is located in route 128.
underwater
The sanctum!
no
by precipitation
Use Dive.
Anything below 18oC (65oF).This is independent from water, unless you're in an underwater swimmingpool livingroom.
When an alligator hibernates, it will find a cool damp cave to stay in, not underwater.
In the underwater cave.