The main causes
- Slow drying (high humidity, still air, short window).
- Overloading (fabric folded over rails, no airflow).
- Re-wetting (evening dampness, dew, light drizzle).
- Machine dwell (left wet in the drum too long before hanging).
Detergent and residue
Too much detergent or softener can leave residue that traps odours. If towels smell musty even after “drying”, try a smaller dose and an occasional hot maintenance wash (if fabric care allows).
How to prevent it
- Max spin and shake items out before pegging.
- Leave gaps and avoid folds.
- Bring in before evening dampness if anything is borderline.
More guides
Pollen, hay fever and line drying
What the pollen tile means, UK bands by type, and tips for sensitive households.
Can washing dry outside when it’s cold?
Cold-but-dry days, winter drying, and when it’s still worth trying.
What is the best time of day to put washing out?
Morning vs afternoon drying, daylight, temperature, and dew.
Should you bring washing in before sunset?
Evening cooling, rising humidity, dew formation, and why washing can feel damp again.
Does laundry dry better on cloudy days?
Yes sometimes - if wind and humidity are favourable.
How to dry towels and bedding outside properly
Heavy-load tips: spacing, pegging, turning, and avoiding damp patches.
Rain risk explained: when is it worth chancing the washing line?
Drizzle vs showers, probability, and short drying windows.
How to line-dry clothes faster: small changes that actually help
Actionable tips: extra spin, shake out, gaps, hangers, face into the breeze.
Why washing dries faster in wind than in sunshine
Why a breezy cloudy day can beat a still sunny one.
Humidity: the hidden reason washing stays damp
Relative humidity, dew point, and why “muggy” air is poor for drying.
Why does my washing smell like "outside"?
A UK guide to fresh vs musty line-dry smells.
Line-drying in 5°C ("freeze-drying")
What’s realistic near freezing, and tips that help.
Does UV light kill bacteria on clothes?
What sunlight can (and can’t) do for hygiene.