St. Swithin's Day is a story written by Grant Morrison and drawn by Paul Grist in 1989 for Trident Comics.

We first meet the lead character, a teenager (who is not given a name in the story) shoplifting a copy of Catcher in the Rye from a London bookshop.

During the course of the story we find out that the teenager is from an unnamed northern British town or city, stealing his housemates' unemployment benefits to come to London to assassinate Margaret Thatcher while she makes a public appearance at a technical college.

It is raining on the day and the teenager manages to get near to Thatcher and starts to pull out what the reader thinks is the previously seen gun.

The last scenes are of the teenager traveling on a train on a sunny day and his final lines are "I don't care if it rains.