Why (and how) does dew form?

Asked by: Erin Beach, Highlands

During the day, water evaporates from rivers and lakes, and plants pull it up through their roots and release it from their leaves. In the evening, the air cools and can’t hold as much water vapour. The excess condenses into water droplets, which collects on any cold surfaces near the ground, where there is less wind.

Read more:

• Is it better to walk or run in the rain?
• What colour is water?

Subscribe to BBC Focus magazine for fascinating new Q&As every month and follow @sciencefocusQA on Twitter for your daily dose of fun facts.