Relative humidity, in plain English
Relative humidity (RH) is how “full” the air is compared to what it could hold at that temperature. Higher RH means the air has less capacity to take on moisture from wet fabric.
Dew point matters
Dew point is the temperature where moisture starts condensing. When air temperature and dew point are close, drying slows and evening dampness arrives quickly.
Practical takeaway
If it feels muggy and still, don’t expect miracles. Look for a breezier slot or finish indoors with airflow rather than leaving laundry out into the evening.
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.
Why washing sometimes smells damp after drying outside
Slow drying, bacteria, detergent residue, and re-wetting.
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.
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.