Sunlight contains ultraviolet (UV) radiation and it is this that causes colours to fade. In summer there is obviously a lot more UV radiation than in winter. Further, since the days are longer in summer, you are likely to have clothes fade more in summer than in winter. It is not just clothes hanging on the line to dry that fade. While you are out in the sun, the clothes you are wearing are being exposed to UV radiation and consequently are quietly fading.

Reducing Fading While you cannot really do much to stop clothes fading while you wear them other than perhaps buying a very large hat or sombrero, you can take some steps to reduce fading when you hang your clothes out to dry after washing them. As a first step, turn your clothes inside out when you hang them out to dry. Any fading which occurs on the inside of the garment is not likely to be noticeable. If you have a rotary clothes line, hang your darker coloured clothes on the inner lines and the lighter coloured clothes on the outer lines. The clothes on the outer lines act as a shade for the inner lines and reduce the amount of sunlight they are exposed to.

If you have a fixed clothesline you will know the direction from which the sunlight comes for the time of day when you are drying your clothes. Simply hang the white or lighter coloured clothes in a position so that, as much as possible, they come between the darker clothes and the sun. Finally, do not leave the darker clothes on the line for longer than it takes to dry them. In summer especially, clothes are often dry in under an hour and so don't need to be left out for the whole day.