I live just outside London and manage to line dry laundry for about 6 months a year (April to Octoberish).

Save energy, smells better, and sunlight seems to result in better stain removal/whiter whites.

It's a bit marginal in Apr and Oct but I line dry close to 100% of washes May to Sept. Even most days in winter if it's sunny it works pretty well.

> 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.

It works in low humidity, but it doesn’t result in the same pleasant smell, as the paper explains.

For those downvoting me, you’d do good to read the paper which is the subject of this discussion.

It clearly states that UV/sunlight exposure is crucial for the pleasant “dried linen” smell, and half of the northern hemisphere does not receive enough UV during winter (check any UV/vitamin D map).

Personal anecdotes notwithstanding; I’m not saying clothes won’t dry in the winter, you just won’t get the same results.

The Amish and many Mennonite communities in the US dry clothes outside all year. It's quite amusing to see their frozen sheets on lines if you take the train between Philadelphia and Harrisburg and further west to Pittsburgh.

My sister in law doesn't own a dryer, and lives in New Hampshire. You can line dry all year long, at least at her lattitude.