I remember being in Connemara in in March in 1970 and being hit by a few days of unseasonal snow.
It was explained to me by my host, Seosamh O Tuairisc, that these were Laethanta an Bó Riabhaigh, the days of the Brindled Cow.
The same cow, having complained about the weather all winter at last relaxed in the balmy days of early Spring in March.
With that some winter weather arrived and, defences down, the old cow was overtaken by the cold and died of what we would now call hypothermia.
I think of this nearly every year when we have our brindled cow days, like we are having now.