Why does my cat drink warm water?

Because it’s all comfy and doesn’t make her cold.

Like @zenvelo said warm water might be soothing or it may be reminiscent of when she was a kitten and nursing warm milk from her mother.

Maybe a dental issue. I have had some dental problems where cold was a huge issue.

I’m guessing it’s a comfort thing. People love hot drinks of all kinds, so why wouldn’t animals like warm drinks as well?

May be because your cat is feeling more comfortable drinking warm water.