Since 1971, the average monthly temperatures have been monitored in Ireland. For January, the average monthly temperature is 7.5 Centigrade. For February the average has been 8, March is 10 degrees Centigrade and April is 12. May hits 14.5 while June, July and August all increase to 16.5, 19 and 18, respectively. September, October, November and December have all seen averages of 16, 14, 10 and 7.5 C.
The North part of the country sees slightly difference averages to the southern half. Malin Head in the far north of Ireland has daily averages of 11.8 degrees Centigrade over the course of a year. Roches Point in the far south of the country has daily averages of 12.8 over the year, making the south 1 degree warmer than the north.
Based on the 14 major weather stations around the entire country, the average daily temperature across the year ranges from 11.8 in the south to 13.8 in the north. Taking all these weather station figures into account, it can be reasonably argued that the average daily temperature in Ireland is 12.7 degrees Centigrade or 55 degrees Fahrenheit.