Dear Tom,

Since I was a small child, my grandmother would say, "If it rains on Easter Sunday, it will rain seven Sundays after." Is this true?

— Maria Webster

Dear Maria,

In the big picture it is not true, but with the help of Chicago climatologist Frank Wachowski we were able to confirm that is has happened at least once. Weather tends to run in cycles with a parade of weather systems every few days often accounting for same-day precipitation events, but the repetitive pattern almost always breaks down after a few weeks. Wachowski found that in 1943, 0.07 inches of rain fell on Easter Sunday, April 25, and rain fell not only on the next seven Sundays but for 11 straight Sundays through July 11. Ten of the 11 Sundays had measurable precipitation with a trace of rain recorded on Sunday, July 4.