Climate of United States of America

Mostly temperate, but tropical in Hawaii and Florida, arctic in Alaska, semiarid in the Great Plains west of the Mississippi River, mediterranean in coastal California, and arid in the Great Basin of the southwest; low winter temperatures in the northwest are ameliorated occasionally in January and February by warm chinook winds from the eastern slopes of the Rocky Mountains.

Terrain: vast central plain, mountains in west, hills and low mountains in east; rugged mountains and broad river valleys in Alaska; rugged, volcanic topography in Hawaii HJH.