The caverns are 54 degrees year round. Jean's and a jacket are perfect. It's pretty wet in the caves, too. Consider wearing some boots for the puddles.
Mid 50's year round
Around mid 50's
We went in jeans and a sweatshirt during May and were comfortable.
Somewhere i saw it as around 55 to 60 degrees. It is closed in winter though.
Thanks! Your answer is awaiting moderation.