yes - water in the pipe condensing out......how empty is the cylinder as you may want to exchange for one with a winter mix of 60% propane 40% butane and, yes, they do vary it for temperature performance as butane liquifies at only -4C.7
Wrap your valve/regulator and any exposed pipe with a bit of insulating foam/tubing would help you through the winter months, failing no tubing, old rags.