Question

why clothes do not dry on a cloudy day

Answer 1

on a cloudy day the humidity is very high and for evaporation humidity must be very less so it takes more time to dry clothes

Answer 2

Wet clothes dry by evapoarting water from them. The higher the temperature and the lower the humidity the faster they dry. On a cloudy i.e. non sunny day, the humidity, or water content, even indoors, is high, so they dry slower