Physical Geography

Ireland, like most of the British Isles, was glaciated during the last Ice Age. As a result, glacial debris covers much of the land. The interior consists primarily of lowlands with plains, rolling land, and hills. Nearly everywhere elevations are less than 300 feet (90 m). Ireland's coastal areas, in contrast, are marked largely by highlands and mountains. In some areas, especially the southwestern coast, they descend abruptly into the sea. The highest peak is 3,414-foot (1,041-m) Carrantuohill, in Macgillycuddy's Reeks, a mountain range in the southwest.

The Shannon is Ireland's largest river. It drains the entire central plain and flows into the Atlantic through a wide estuary near Limerick. Other main streams include the Blackwater, Suir, Nore, Barrow, Slaney, Liffey, and Boyne. Among the many loughs (lakes) are Corrib, Derg, Mask, and Ree. Numerous bays indent the coast.

Ireland has a maritime climate. Because of the temperate surrounding waters, it is particularly mild for such a northerly location. Average January temperatures are around 40° F. (4° C.); average July temperatures, about 60° F. (16° C.). Extreme heat or cold is unusual. Overcast skies, high humidity, and much rain are typical. Annual precipitation ranges from 30 inches (760 mm) at Dublin, the capital, to 80 inches (2,030 mm) in the western highlands. Snows are light and infrequent.

Bogs are extensive, and moors, consisting mainly of heather and bilberry, cover much of the higher and wetter lands. There is hardly any forest.