April the fourth month of the year, in the northern hemisphere usually considered the second month of spring, often referred to allusively as characterized by changeable weather, with sudden showers and sunshine.
April Fool's Day 1 April, in many Western countries traditionally an occasion for playing tricks. This custom has been observed for hundreds of years, but its origin is unknown. It is also called All Fools' Day.
April showers bring forth May flowers traditional weather rhyme, recorded from the mid 16th century, asserting the importance of rain in early spring for growing plants.

A·pril / ˈāprəl/ • n. the fourth month of the year, in the northern hemisphere usually considered the second month of spring: the prison was to close in April | [as adj.] April showers.

April XIV. — L. Aprīlis, prop. adj. (sc. mēnsis month).