The climate of Virginia, a state on the east coast of the United States, is mild compared to more northern areas of the United States such as New England and the Midwest. Most of Virginia east of the Blue Ridge mountains, the southern part of the Shenandoah Valley, and the Roanoke Valley, has a humid subtropical climate. In the mountainous areas west of the Blue Ridge, the climate is warm-summer humid continental or oceanic climate. Severe weather, in the form of tornadoes, tropical cyclones, and winter storms, impacts the state on a regular basis. Central Virginia received significant snowfall of 20 inches in December 2009.
The climate of Salt Lake City, Utah features cold and snowy winters, hot and dry summers, and modest to light seasonal rainfall. Lying in the Salt Lake Valley, the city is surrounded by mountains and the Great Salt Lake. Under the Köppen climate classification, Salt Lake City has either a Mediterranean climate (Csa) or dry-summer continental climate (Dsa) depending on which variant of the system is used, though it borders on a cold semi-arid climate (BSk) due to the city's relatively low precipitation.
The climate of California varies widely from hot desert to alpine tundra, depending on latitude, elevation, and proximity to the Pacific Coast. California's coastal regions, the Sierra Nevada foothills, and much of the Central Valley have a Mediterranean climate, with warmer, drier weather in summer and cooler, wetter weather in winter. The influence of the ocean generally moderates temperature extremes, creating warmer winters and substantially cooler summers in coastal areas.
The climate of San Diego, California, is classified as a hot-summer Mediterranean climate. The basic climate features hot, sunny, and dry summers, and cooler, wetter winters. However, San Diego is much more arid than typical Mediterranean climates, and winters are still dry compared with most other zones with this type of climate. The climate at San Diego International Airport, the location for official weather reports for San Diego, as well as the climate at most beach areas, straddles the border between BSh and BSk due to the mild winters and cool summers in these locations.
The characteristics of United States rainfall climatology differ significantly across the United States and those under United States sovereignty. Summer and early fall bring brief, but frequent thundershowers and tropical cyclones which create a wet summer and drier winter in the eastern Gulf and lower East Coast. During the winter, and spring, Pacific storm systems bring Hawaii and the western United States most of their precipitation. Low pressure systems moving up the East Coast and through the Great Lakes, bring cold season precipitation to from the Midwest to New England, as well as Great Salt Lake. The snow to liquid ratio across the contiguous United States averages 13:1, meaning 13 inches (330 mm) of snow melts down to 1 inch (25 mm) of water.
The climate of Houston is classified as a humid subtropical climate, with tropical influences. August normally ranks as the warmest month at an average temperature of 95 °F (35 °C) and January the coldest month at an average temperature of 63 °F (17 °C).
The climate of the north and central parts of the U.S. state of Florida is humid subtropical. South Florida has a tropical climate. There is a defined rainy season from May through October when air-mass thundershowers that build in the heat of the day drop heavy but brief summer rainfall.
Texas' weather varies widely, from arid in the west to humid in the east. The huge expanse of Texas encompasses several regions with distinctly different climates: Northern Plains, Trans-Pecos Region, Texas Hill Country, Piney Woods, and South Texas. Generally speaking, the eastern half of the state is humid subtropical, while the western half is largely semi-arid.
The climate of the United States varies due to changes in latitude, and a range of geographic features, including mountains and deserts. Generally, on the mainland, the climate of the U.S. becomes warmer the farther south one travels, and drier the farther west, until one reaches the West Coast.
The climate of North Carolina is varying, from the Atlantic coast in the east to the Appalachian Mountains in the west. The mountains often act as a "shield", blocking low temperatures and storms from Canada and the Midwest from entering the Piedmont and Coastal Plain of North Carolina.
The climate of Pennsylvania is diverse due to the multitude of geographic features found within the state. Straddling two major climate zones, the southeastern corner of Pennsylvania has the warmest climate. A portion of Greater Philadelphia lies at the southernmost tip of the humid continental climate zone, with the city proper being in the humid subtropical climate zone. Still, Philadelphia features colder, snowier winters than most locations with a humid subtropical climate. Moving west toward the mountainous interior of the state, the climate becomes markedly colder, the number of cloudy days increases, and winter snowfall amounts are greater.
South Carolina has a humid subtropical climate, with hot summers throughout most of the state. But, an exception does occur in the Blue Ridge Mountains, as outlier pockets of an Oceanic Climate do exist. Mild winters predominate in the eastern and southern part of the state, but cool to occasionally cold winters are the standard in the northwestern area of the state, especially areas at or above 600 feet in elevation. On average, between 40 and 80 inches of precipitation falls annually across the state, potentially even in excess of 100 inches in portions of the Appalachian temperate rainforest. Tropical cyclones, and afternoon thunderstorms due to hot and humid conditions, contribute to precipitation during the summer and sometimes fall months, while extratropical cyclones contribute to precipitation during the fall, winter, and spring months. The coast experiences nearly all of their tropical weather impacts from storms coming directly from the Atlantic coast. The northwestern area of the state can receive impacts from both Atlantic basin storms moving westward from the coast and also occasionally very heavy rainfall and flooding from storms originating from the Gulf of Mexico that move inland towards the northeast after making landfall from the Florida Panhandle to Louisiana.
The climate of New York (state) is generally humid continental, while the extreme southeastern portion of the state lies in the warmer humid subtropical climate zone. Winter temperatures average below freezing during January and February in much of the state of New York, but several degrees above freezing along the Atlantic coastline, including New York City.
The climate of Massachusetts is mainly a humid continental climate, with hot, humid summers, cold, snowy winters and abundant precipitation. Massachusetts is a state located in the New England region of the northeastern United States. Most of its population of 7 million live in the Boston metropolitan area. The eastern half of this relatively small state is mostly urban and suburban. Massachusetts is the most populous of the six New England states and ranks third in the nation by population density and fourth by GDP per capita. Massachusetts receives about 43 inches or 1,090 millimetres of rain annually, fairly evenly distributed throughout the years, slightly wetter during the winter. Summers are warm with average high temperatures in July above 80 °F or 26.7 °C and overnight lows above 60 °F or 15.6 °C common throughout the state. Winters are cold, but generally less extreme on the coast with high temperatures in the winter averaging above freezing even in January, although areas further inland are much colder. The state does have extreme temperatures from time to time with 100 °F or 37.8 °C in the summer and temperatures below 0 °F or −17.8 °C in the winter not being unusual.
The climate of Miami is classified as having a tropical monsoon climate with hot and humid summers; short, warm winters; and a marked drier season in the winter. Its sea-level elevation, coastal location, position just above the Tropic of Cancer, and proximity to the Gulf Stream shape its climate.
The state of Alabama is classified as humid subtropical (Cfa) under the Köppen climate classification. The state's average annual temperature is 64 °F (18 °C). Temperatures tend to be warmer in the state's southern portion with its proximity to the Gulf of Mexico, while its northern portions, especially in the Appalachian Mountains in the northeast, tend to be slightly cooler. Alabama generally has hot, humid summers and mild winters with copious precipitation throughout the year. The state receives an average of 56 inches (1,400 mm) of rainfall each year and experiences a lengthy growing season of up to 300 days in its southern portion. Hailstorms occur occasionally during the spring and summer here, but they are seldom destructive. Heavy fogs are rare, and they are confined chiefly to the coast. Thunderstorms also occur year-around. They are most common in the summer, but they are most commonly severe during the spring and late autumn. That is when destructive winds and tornadoes occur frequently, especially in the northern and central parts of the state. Central and northern Alabama are squarely within Dixie Alley, the primary area in the U.S. outside the Southern Plains with relatively high tornado risk. Alabama is ranked second in the U.S for the deadliest tornadoes. Hurricanes are quite common in the state, especially in the southern part. Major hurricanes occasionally strike the coast, such as Hurricane Frederic in September 1979 and Hurricane Ivan in September 2004; both storms resulted in significant to devastating damage in the Mobile area.
The U.S. state of Hawaiʻi, which covers the Hawaiian Islands, is tropical but it experiences many different climates, depending on altitude and surroundings. The island of Hawaiʻi for example hosts four climate groups on a surface as small as 4,028 square miles (10,430 km2) according to the Köppen climate types: tropical, arid, temperate and polar. When counting also the Köppen sub-categories – notably including the very rare cold-summer mediterranean climate – the island of Hawaiʻi hosts 10 climate zones. The islands receive most rainfall from the trade winds on their north and east flanks as a result of orographic precipitation. Coastal areas are drier, especially the south and west side or leeward sides.
The climate of Allentown, Pennsylvania is classified as a humid continental climate. Allentown's warmest month is July with a daily average temperature of 74.7 °F (23.7 °C) and the coldest month being January with a daily average of 29.4 °F (−1.4 °C). The average precipitation of Allentown is 45.35 inches (1,152 mm) per year.
The Geography of Atlanta encompasses 132.4 square miles (342.9 km2), of which 131.7 square miles (341.1 km2) is land and 0.7 square miles (1.8 km2) is water. The city is situated among the foothills of the Appalachian Mountains, and at 1,050 feet (320 m) above mean sea level, Atlanta has the highest elevation among major cities east of the Mississippi River. Atlanta straddles the Eastern Continental Divide, such that rainwater that falls on the south and east side of the divide flows into the Atlantic Ocean, while rainwater on the north and west side of the divide flows into the Gulf of Mexico. Atlanta sits atop a ridge south of the Chattahoochee River, which is part of the ACF River Basin. Located at the far northwestern edge of the city, much of the river's natural habitat is preserved, in part by the Chattahoochee River National Recreation Area.
The climate of New England varies greatly across its 500-mile (800 km) span from northern Maine to southern Connecticut.
