> In most of the northern hemisphere it will only be viable for a couple months in the summer.
This is not correct. I've done line drying year-round, doesn't work great when it's below zero (freezes) but otherwise works fine. I think low relative humidity is important so the moisture in the clothing has somewhere to go.
This has been my experience too. It’s humid all year where I live, my clothes either 1)do not get dry or 2) spend so much time wet that a musty smell develops.
This is not correct. I've done line drying year-round, doesn't work great when it's below zero (freezes) but otherwise works fine. I think low relative humidity is important so the moisture in the clothing has somewhere to go.