Condensation: noun; Water which collects as droplets on a cold surface when humid air is in contact with it (Oxford Dictionary).

As I live in an old, Grade-II-listed building that only has single glazing and I don’t like to have my heating on so high that I can wear t-shirts all year round, I sometimes get condensation on the inside of my windows. It can be a bit tedious to deal with but it’s also rather lovely, especially when you look closely and see the outside world reflected upside down in the water droplets.