Pennsylvania is an eastern state lying in both the northern Appalachians and the northeastern Central Lowlands . It is often considered one of the Middle Atlantic states, even though it doesn't border the Atlantic Ocean. The Atlantic Ocean has little effect on Pennsylvania's climate because prevailing westerly winds sweep weather systems eastward from the interior of the continent. Thus, Pennsylvania's climates are generally known as humid continental, with distinct seasonal temperature variations and abundant rain. A verage temperatures in the north range from about 69 F in July to about 25 F in January.
Temperatures are several degrees higher in southern Pennsylvania.
Annual rainfall averages some 39 inches, and prevailing winds are from the west. Philadelphia served as the United States' leading city for many years. The Declaration of Independence was signed in Philadelphia, the home of the Liberty Bell. But its prosperity has long been based on its fertile farmland and forests. Nearly a third of Pennsylvania is under cultivation.