Donald R. Howard (1927-1987), Chaucer: His Life, His Works, His World
(New York: Fawcett Columbine, 1989), p. xv:
And facts, like everything else, go out of fashion. In the 1960s it was reckoned a fact that "the drought of March," referred to in the opening lines of The Canterbury Tales, was a purely rhetorical convention drawn from the literature of Mediterranean countries where March is a dry month; England, hardly ever dry, certainly suffers no droughts in March. It was one of the best facts going, and it produced a corollary fact, that Chaucer's poetry, like all medieval poetry, is bookish and conventional—we must not expect actualities in it. These facts were printed in textbooks and taught in universities; I taught them myself, alas. Then it occurred to one scholar that March in England may be dry in some places; to another that weather may have changed since Chaucer's day; and to another that the word "drought" in Middle English meant not total lack of rain but only dryness. Actually, Chaucer lived in the "Little Ice Age," which came over Europe early in his century and lasted until the end of the seventeenth century. It brought a shorter growing season. March was dry, in some places still is. Farmers counted on this relatively dry period for planting; it was, a folklorist discovered, as proverbial in England among farmers as in Mediterranean countries among poets, and so were April showers. Realism, banished from the opening lines of The Canterbury Tales for a decade or so, was permitted reentry. The drought of March became a fact again.