Average annual temperature is about 9 °C. In the middle and east of the country temperatures tend to be somewhat more extreme than in other parts of the country. For example, summer mean daily maximum is about 19 °C and winter mean daily minimum is about 2.5 °C in these areas.

Mean annual windspeed varies between about 4 m/sec in the east midlands and 7 m/sec in the northwest. Strong winds tend to be more frequent in winter than in summer. Sunshine duration is highest in the southeast of the country. Average rainfall varies between about 800 and 2,800mm.

With southwesterly winds from the Atlantic dominating, rainfall figures are highest in the northwest, west and southwest of the country, especially over the higher ground. Rainfall accumulation tends to be highest in winter and lowest in early summer.

The annual number of days with more than 1 mm of rain varies between about 150 in the drier parts and over 200 in the wetter parts of the country. Met Éireann has station data, dating back to the 19th century, for a number of stations.

The diagram below shows the mean annual temperature for one of them (Malin Head) expressed as the departure from the 1961 to 1990 normal in degrees Celsius. The black line is the average of the 15 year period centred on the year in question.