World Book Day is well underway today despite the extreme weather conditions in the UK. This is the 21st year the event has been run and was created by The United Nations Educational, Scientific and Cultural Organization.

Whilst there are a host of impressive objectives from World Book Day such as promoting literature and celebrating authors, the day is best known for the tradition of dressing up as a character for children and teachers.

Here is a collation of this year's contributions on social media.

Even adults got into the spirit.

What's more, even authors and celebrities have come out to support the day.

It seems that a little snow isn't getting in the way of people celebrating the big day.