A household weather service of absolutely no authority

🧺 The Peg-O-Meter

Will your washing dry, or are you just decorating the garden with damp cotton?

Enter a few forecast details and let the Peg-O-Meter weigh up the sunshine, breeze, temperature and general attitude of the atmosphere. Rough estimates are absolutely fine. It won't fold the laundry for you. We've checked.

What's the weather up to?

Type the forecast temperature. The little arrow buttons are optional; typing is much quicker.
Highest temperature during the same period. Whole degrees are usually accurate enough.
Use the daytime forecast, not an overnight or early-morning reading. A rough average is fine.
Use the average daytime wind speed in mph, not the strongest gust. A gust that steals your pants is a different problem.
What's the sky doing?
Choose the description that best matches the daylight forecast. The calculator treats these as rough estimates from 0% to 100% cloud cover. No cloud-counting qualifications required.
Enter hours, in half-hour steps if useful. How long can the washing realistically stay out in daylight?
How sunny is the spot where the line hangs?
Think about the actual place the clothes hang. A sunny garden corner and a shaded side passage are different worlds.
Any rain forecast during that time?
A covered line is a different story, but this calculator assumes the washing is out in the open.
Think about thickness rather than just the material. A thin cotton T-shirt is lightweight; a thick cotton towel is heavyweight. This changes the laundry advice, not the weather score.
—out of 100

Your laundry verdict

This is a weather-opportunity score, not a percentage chance of drying or a measure of how much moisture will be removed.

What's helping – and what's getting in the way?

The quick-and-dirty washing rule

A bit of warmth + air movement + whatever sunshine you can get + enough daylight = give the pegs a chance. Cold alone doesn't cancel laundry day.

Air needs room for more water

Humidity matters, but temperature matters too. Cold air at 89% humidity is not equivalent to warm air at 89%. The calculator combines both rather than using a humidity cut-off on its own.

A breeze does the legwork

Moving air carries away the moist layer sitting around the fabric. A steady breeze helps; a gale that launches your pillowcase into next door's garden is less ideal.

Sunshine gives it a boost

Sunlight can warm the fabric and its moisture, while even bright overcast conditions provide some daylight energy. More useful daylight gives evaporation longer to work.

Why does the calculator care about dew point and vapour-pressure deficit?

Relative humidity is a percentage of how close the air is to saturation at its current temperature. Warmer air can hold more water vapour, so the same relative humidity can mean very different drying conditions on a cold day and a warm day.

The calculator estimates vapour-pressure deficit (VPD): the gap between how much water vapour the air contains and how much it could contain at saturation. A larger VPD generally means a stronger atmospheric pull for evaporation. It also shows an estimated dew point as a familiar cross-check.

This is still a simplified guide. The forecast can change hour by hour, and the air right next to wet fabric can be more humid than the weather app suggests. Use the average conditions for the hours the washing will actually be outside.

A tiny but important disclaimer

The Peg-O-Meter is a helpful guess, not a laundry-based prophecy. No tiny meteorologist lives in your peg basket, and we cannot guarantee your jeans will be dry by tea time.

The score is a simple, weighted guide to the weather opportunity – it is not a percentage chance of success, a measured drying rate or a prediction of how much water your clothes will lose. Actual drying depends on fabric, how well the washing was spun, how far apart the items are, shelter, shade and changing hourly conditions. If something still feels damp, believe the dampness.

Use your judgement around frost, strong winds and changing weather. Secure the washing properly, and don't leave it out if rain is on the way.

Made for people who would rather dry their washing outside than heat the whole house to dry three socks. 🧦