I would like to know when it is good to hang the washing on the line – should be simple – right? Well no, that is very wrong.
Initial Research
I found some good information at The science of drying – how to be a clothes line ninja. There is an image which makes good sense. You have to take into account:
- A dry day – no rain
- Sunshine – low cloud coverage
- Relative Humidity – should be low
- Wind – up to a point – maybe the same cutoff as a kite
- Temperature – warmer is better – greater than 5 maybe
- Dew point lower than the temperature
- Cloud cover less than 60% – maybe
- Hours till sunset more than 3 maybe
But we need numbers if we’re going to write an algorithm. We can’t just go with common sense.
Dew Point
How To Geek has a pretty cool article here. Translated to Celcius, there is a table which reads as follows:
| Dew Point | Comfort |
| Below 10 | Dry |
| 10 – 13 | Comfortable |
| 13 – 16 | Pleasant |
| 16 – 18 | Sticky |
| 19 – 21 | Humid |
| 22 – 24 | Oppressive |
| 24 + | Miserable |
While you’re at it, check out the UV index info here – although this is not directly related to washing,
This is better UV index data but it does not belong on this post: https://www.verywellhealth.com/know-your-uv-index-1069524