Because of the United States' size and varying degrees of latitudes and geographic features, the country experiences a wide range of climates. Generally, overall temperatures are warmer as one travels further south, and the air becomes drier as one moves further west until hitting the west coast.
The Southwest region of the U.S. has a hot desert climate at lower elevations. This region experiences high temperatures and dry air and has many vast desert areas. The country's Southeast region experiences a somewhat sub-tropical climate that includes hot, humid summers (temperatures above 100 are not uncommon) and mild winters. The Northwest is characterized by a diverse climate with bitter, cold winters and somewhat humid, hot summers. The West Coast of the U.S. experiences cool, wet winters and dry, warm summers (with chilly evenings), specifically the further north one goes. The Midwest has humid summers, but winters are long and generally harsh, with temperatures below zero being common, especially in the northern states.
The average temperature in the contiguous United States in 2019 was 52.68 degrees Fahrenheit (°F). The state temperature averages range from 26.6°F in Alaska to 70.7°F in Florida.
The Köppen climate classification is used in this article to describe state climates.
Coldest States in the U.S.
1. Alaska
Alaska is the coldest state in the U.S., with an average temperature of 26.6°F. Alaska has a subarctic climate. During the winter months, Alaska's temperatures can drop as low as -.30°F. The Fairbanks area of Alaska experiences an extremely wide range of temperatures throughout the year, ranging from -50°F in the winter to highs of 90°F in the summer.
2. North Dakota
North Dakota is the U.S.'s second-coldest state. The eastern half of North Dakota experiences a humid continental climate, and the western half experiences a semi-arid climate. The average temperature in North Dakota is 40.4°F, with average temperatures around 24°F in the winter. January is North Dakota's coldest month when temperatures range from 2°F in the northern parts of the state to 17°F in the southern parts.
3. Maine
The third-coldest state in the United States is Maine, where the average temperature is 41°F. Maine's climate classification is humid continental, as is the majority of New England states. In the winter, the average temperature is 12°F. Maine has abundant snowfall in the winter, with an average accumulated snowfall of 10 to 80 inches. The most northeastern city in the United States, Caribou, receives even more snowfall and harsher winter temperatures.
4. Minnesota
Minnesota is the fourth-coldest state in the country. Minnesota's humid continental climate is greatly influenced by its proximity to Canada to its north and Lake Superior to its northeast. The average temperature in Minnesota is 41.2°F, with temperatures dropping as low as -30°F in the northern parts of the state in January.
5. Wyoming
Wyoming is the fifth-coldest state in the United States, with an average temperature of 42°F. Wyoming has a mostly semi-arid climate. During the winter, the average minimum temperatures range from 0°F to 15°F. Winds are typically in the 30 to 40 mile per hour range, with gusts up to 50 to 60 miles per hour, significantly reducing the temperature. Additionally, Wyoming's highlands and mountaintops can receive up to 200 inches of snow per year, and lowlands can receive up to 50 inches of snow.
Hottest States in the U.S.
1. Florida
Florida is the hottest state in the U.S., with an average annual temperature of 70.7°F. As the southernmost contiguous state in the U.S., Florida has a sub-tropical climate in its northern and central parts and a tropical climate in its southern parts. Florida has mild winters and extremely hot summers, especially during its hottest month of July, where temperatures reach average highs of 90°F to 92°F, and it is not uncommon for temperatures to hit or go above 100°F.
2. Hawaii
Hawaii is the second-hottest state in the United States, with an average annual temperature of 70.0°F. Hawaii experiences four different Köppen climate zones: tropical, arid, temperate, and polar. In the summer, temperatures in Hawaii peak around 84°F and typically do not rise above 90°F. In the winter, high temperatures are usually around 79°F, and lows rarely drop below 65°F. Hawaii has never recorded a temperature below freezing (32°F).
3. Louisiana
With an average annual temperature of 66.4°F, Louisiana is the third-hottest state in the United States. Louisiana has a subtropical climate with long, hot, and humid summers and short, mild winters. August is Louisiana's hottest month, where average highs range from 89°F to 94°F. Louisiana's position on the Gulf of Mexico gives it a considerable wet season and high humidity that can make the heat feel like 120°F.
4. Texas
Texas is the fourth-hottest state in the United States, with an average annual temperature of 65.3°F. Texas has arid and semi-arid climates in its west and humid and sub-tropical climates in its east. August is Texas's hottest month, where average high temperatures are in the 93°F to 101°F range. In January, Texas's coldest month, the average high temperatures are between 52°F and 71°F.
5. Georgia
Located just north of Florida, Georgia is the fifth-hottest state in the United States, with an average annual temperature of 63.5°F. In its northeast, Georgia has an oceanic climate and a humid subtropical climate in the rest of the state. Summers in Georgia have average highs ranging from 72°F to 82°F in the northeast region and 90°F to 100°F in the south.