Everyone knows about Punxsutawney Phil, but who knows about Chesapeake Charlie? If Charlie sings on June 21, it means a wet summer ahead.
Okay, okay … so maybe I made up the bit about Chesapeake Charlie, the not-so-famous weather forecasting cuckoo. But even if it is not as well-known as the old story that a groundhog seeing his shadow on February 2 means more winter, folklore says that if a cuckoo sings on June 21 (which is also summer solstice, of course), it will be a wet summer. How did you not know this already?
And summer solstice, of course, is the longest day and shortest night of the year. The sun begins its annual retreat, passes the autumn equinox when day and night are of equal length, and begins to return after winter solstice, the shortest day and longest night of the year. (Spring equinox, of course, is the date on which day and night are equal length again.)
Summer Solstice by Stuccoloco