This is my first spring in the Rhine Valley. They say it arrives sooner here than anywhere else at the same latitude in Germany, advancing northwards as a green tongue extending up the valley, and caused by the Fohn effect of the high mountains on either side of the flat, broad catchment area.
So far the green has not arrived, but the cherry blossoms are in bloom, the daffodils are out, and all around is the palpable, contagious optimism of a reawakening world.
Even the hardest, most impervious heart can empathise with the antics of young Master Fenton, as described by mine cheerful host of the Garter Inn in The Merry Wives of Windsor: "He capers, he dances, he has eyes of youth, he writes verses, he speaks holiday, he smells April and May."
But anywhere in the temperate latitudes we should not rejoice too soon or cast too many clouts for yet a week or two. Sometimes at this time of year winter has one final fling, and a harshness more appropriate to the dismal depths of February spills over unexpectedly into would-be gentleness of early April.
Our Irish ancestors had a name for this phenomenon: they called it Laethanta na Bo Riabhai.
March, it seems, was once rather shorter than it is now, and once upon a time, at the beginning of the old April, the Bo Riabhach - the brindled cow - began to grumble to her bovine friends about the harshness of the previous month.
March at first took little notice, but as the crescendo of complaint increased, March understandably took pique and resolved to teach the cow a lesson. It duly borrowed three days from April, and made them so wet and cold and stormy that the Bo Riabhach perished from this unprecedented harshness of the elements.
The volatility of Irish weather in late March and early April is also implicit in the notion of the "blackthorn winter". Ancient wisdom had it that there were generally a few mild days towards the end of March which brought the blackthorn bushes into bloom. But these, it seems, were invariably followed by a cold, harsh period traditionally known as the blackthorn winter.
In Scotland this unwelcome snap is sometimes called the "Peewit's Pinch". The peewit is a kind of plover, onomatopoeically named from its distinctive cry, and it often feels the pinch when a few days of cold winds and frosty weather come upon it unexpectedly, just as it is about to build its nest upon the Scottish moors.