St. Swithin's Day

[swith-uh nz]
  1. July 15, superstitiously regarded as a day that, should it rain or be fair, will be followed by 40 consecutive days of like weather. Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

British Dictionary definitions for saint swithin's day

Saint Swithin's Day

noun usually abbreviated to: St Swithin's Day
  1. July 15, observed as a Church festival commemorating Saint Swithin. It is popularly supposed that if it rains on this day the rain will persist for the next 40 days
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012