It is gonna be 27 degrees tomorrow morn here in N. FL. so maybe too
cold for boating.
However, great for looking for caves. All the snakes are too cold to
move.
Another way it works is that on very cold mornings with dry air, the
caves actually blow air out that is more humid and warmer than the
outside air. So, one can find caves on mornings like this by looking
for the condensing water vapor near them.
Mostly, it is the snakes being too cold to move.