Physical Geography

New Hampshire lies in the northernmost section of the diverse Appalachian region of the United States. It is an old, eroded area where glaciers formed or modified many of the physical features in recent geologic time. Advancing ice sheets smoothed hills and mountains and in places leveled the land. Receding, they dammed rivers, created lakes, and left widespread debris in such forms as moraines and drumlins.

There are three major physical regions in New Hampshire:

The Seaboard Lowland is a relatively narrow strip of land in the southeast. Sandy beaches and rocky promontories line the coast. Inland, the terrain consists of flat to rolling land dotted by occasional low hills. Seven miles (11 km) offshore are the barren Isles of Shoals, three of which are part of New Hampshire and the rest of Maine.

The New England Upland is a rolling to hilly plateau region covering the rest of the southern half of the state. Elevations increase toward the west, and range generally betweeen 500 and 1,500 feet (150 to 450 m). Rising even higher are numerous isolated mountains called monadnocks. In the southwestern corner of the state stands Monadnock Mountain, from whose name comes the term for all such mountains.

The White Mountains form a picturesque highland region in northern and central New Hampshire. Chief among the ranges is the Presidential Range, which trends northeast-southwest. Generally rounded but occasionally rugged, the White Mountains contain high peaks, deep ravines, and huge U-shaped troughs or passes locally called notches. Among them are Crawford, Franconia, and Pinkham notches. Mount Washington, in the Presidential Range, rising well above the timberline to 6,288 feet (1,917 m) above sea level, is the highest peak in New England and one of the loftiest in the eastern United States.

Five major rivers, with their tributaries, drain the state: the Connecticut, Merrimack, Piscataqua, Saco, and Androscoggin. The Connecticut from its source in the north flows south along the Vermont-New Hampshire border, draining the west. Central and southern New Hampshire is drained by the Merrimack. The short, tidal Piscataqua, on the Maine-New Hampshire border in the southeast, funnels the waters of numerous rivers into the Atlantic. In the north, the Saco and Androscoggin rivers flow eastward and reach the Atlantic through Maine.

Dotting the state are more than 1,000 lakes, mostly of glacial origin. The largest is Lake Winnipesaukee. Other lakes include Newfound, Ossipee, Squam, Sunapee, Umbagog, and Winnisquam. As in the rest of New England, many of the small lakes are called ponds. The chief reservoirs are Francis and First Connecticut lakes and Moore and Blackwater reservoirs.

New Hampshire has a continental climate similar to that occurring throughout New England. It is marked by long, cold winters; short, warm summers; highly changeable weather; and ample rainfall evenly distributed throughout the year. In the south, the Atlantic Ocean has a tempering effect, especially along the coast. The climate is more severe in the north because of the latitude and increased elevation.

Average January temperatures range from about 10° F. (-12° C.) in the north to 25° F. (-4° C.) in the south. Except along the coast, temperatures often drop below 0° F. (-18° C.). July temperatures average 65° to 70° F. (18° to 21° C.) throughout most of the state. Only occasionally are there readings of more than 90° F. (32° C.).

Some mountainous areas receive more than 70 inches (1,780 mm) of precipitation each year. Most of New Hampshire, however, gets 40 to 45 inches (1,020 to 1,140 mm). Deep snow covers the ground all winter, particularly in the mountains. Among the destructive storms that occasionally strike the state are hurricanes, northeasters, and tornadoes.

Although virgin forests were cleared long ago, New Hampshire retains most of its native vegetation. Forests are composed of mixed deciduous hardwoods and conifers. Sugar maple, birch, beech, and various oaks and hickories predominate; spruce, fir, and eastern white pine are also common. A great variety of wild flowers, including daisies, violets, and goldenrod, grow throughout much of New Hampshire.