How long does washing take to dry outside?
On a good drying day, two to four hours for most of a load. Thin cotton and synthetics can be done in an hour; towels, jeans and bedding often need five or more, and are what decides whether you get it all in before evening.
It depends on the fabric, not just the day
A cotton t-shirt holds a fraction of the water a bath towel does, so the same conditions produce wildly different times across one load. That is why a single estimate for the whole wash is close to useless.
Rough guide on a good day: synthetics and gym gear 45 minutes to an hour and a half, thin cotton one to two hours, shirts and trousers two to three, bedding three to four, jeans and towels four to six.
What stretches those times
Humidity is the big multiplier. Going from 50% to 75% can double the time for a thick item without changing anything else. Still air does the same, because washing wraps itself in a thin skin of humid air as it dries, and without a breeze that skin just sits there.
Hanging matters more than people think. A towel folded double over the line dries at roughly half the rate of one hung flat, because you have halved the surface area meeting the air. Give sheets the longest run of line you have and shake them out halfway through.
Working out your own finish time
The practical version: take the thickest item in the load, estimate from the guide above, then check whether that finish time lands before the drying rate falls away in the late afternoon. If it does not, either put the thick items in first on their own or accept they are coming in damp.
Washcast does this per garment rather than per load, which is the part no free weather app will tell you.
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