Record temperatures for March were set at the weekend, says Met Éireann.
On Saturday, it touched 20.7 degrees in Valentia, the highest March temperature since records began there more than a century ago.
In Belmullet, it reached 19.5 degrees, Kilkenny 19.2 degrees and Knock 18.6 degrees - all record temperatures for March since records began in those locations in 1965.
In Rosslare, however, it was just 8.7 degrees on Saturday because of lingering fog.