Overall, Ireland has a mild, but changeable, climate all year. The island experiences few weather extremes. The warmest recorded air temperature was 33.3°C (91.94°F) at Kilkenny Castle, County Kilkenny on 26 June 1887. The coldest air temperature was -19.1°C (-2.38°F) at Markree Castle, County Sligo on 16 January 1881.
Precipitation falls throughout the year, but is light overall, particularly in the east. The west, however, tends to be wetter on average and prone to the full force of Atlantic storms, more especially in the late autumn and winter months, which occasionally bring destructive winds and high rainfall totals to these areas, as well as snow and hail. The regions of North Galway and East Mayo have the highest incidents of recorded lightning annually (5 to 10 days per year). Though not noted for its snowfall, the four provinces of Ireland experience some snowfall each winter, though its intensity varies with Munster in the south recording the least snow with Ulster in the north more prone to snow. Some areas along the south and southwest coasts haven't had any lying snow for the past 16 years, with February 1991 being the last such event.
There are noticeable differences in temperature between coastal and inland areas. Inland areas are warmer in summer, and colder in winter - there are usually around 40 days of below freezing temperatures (0°C) at inland weather stations, but only 10 days at coastal stations. The temperature difference can be seen in very short distances, for example the average daily maximum temperature in July in Omagh is 23°C (73.4°F), while it is only 18°C (64.4°F) in Derry, just 54.1 kilometers (33.6 miles) away. The average daily minimum temperatures in January in these locations also differ, with only -3°C in Omagh and 0°C in Derry. Ireland is sometimes affected by heat waves, most recently 1995, 2003 and 2006.
Average temperatures in the island vary from -4°C (min) to 11°C (max) in January, and 9°C (min) to 23°C (max) in July.
One of the coldest nights for the past few years was recorded on Monday, 5 February 2007 when air temperatures in the capital Dublin dipped to -5ºC (23ºF) with parts of Ulster recording lows of -9ºC (15.8ºF).