The United States
includes a wide variety of climate types due to its large size, range
of geographic features, and non-contiguous arrangement. In the contiguous United States to the east of the 100th meridian, the climate ranges from humid continental in the north to humid subtropical in the south. The southern tip of Florida is tropical. The Great Plains west of the 100th meridian are semi-arid. Much of the Rocky Mountains, the Sierra Nevada, and the Cascade Range are alpine. The climate is arid in the Great Basin, desert in the Southwest, Mediterranean in coastal California, and oceanic in coastal Oregon and Washington. The state of Alaska—on
the northwestern corner of the North American continent—is largely
subarctic, with an oceanic climate in its southern edge and a polar
climate in the north. The archipelago state of Hawaii, in the middle of the Pacific Ocean, is tropical.
Extreme weather is not uncommon—the states bordering the Gulf of Mexico are prone to hurricanes
, and tornadoes regularly occur in the area of the Midwest referred to as Tornado Alley. The United States has more tornadoes than the rest of the countries of the world combined.