Saint Swithin's day, if thou be fair, for forty days it will remain; Saint Swithin's day, if thou bring rain, for forty days it will remain traditional weather rhyme, early 17th century; Saint Swithin was a bishop of Winchester who died in 862, and his feast day is 15 July.
Saint Swithin (both: swĬŧħ´ən), fl. 860, English bishop of Winchester. He was buried, according to his wishes, outside his church, but his relics were later removed to the new cathedral. According to tradition, if it rains on his feast day, July 15, the anniversary of the removal, it will rain daily thereafter for 40 days; if it is fair on St. Swithin's Day, it will not rain for 40 days.