Question: How do icicles form?

Reka Nagy answered on 14 Nov 2016:

Icicles form when snow deposited on surfaces such as roofs starts to melt, but it’s still pretty cold outside – the melted water starts to drip down but freezes due to the cold temperature. The more snow melts and then re-freezes on the already-forming icicle, the bigger the icicle gets!