The Hottest States in the U.S. Battle Humidity on top of High Temps

Florida ranks as the hottest state in the country based on average annual temperature, reaching 71.5°F (21.9°C) between 1991 and 2020. Its humid subtropical climate produces hot summers and mild winters, which keeps temperatures elevated across the entire state year-round.

Summer heat in Florida is intense but consistent. During the summer months—especially June through August—highs often reach 90°F to 92°F (32.2°C to 33.3°C), and humidity pushes the heat index even higher.

Warm ocean waters also play a role. In recent years, rising Atlantic temperatures have contributed to extreme weather and stronger heat waves.

Hawaii is the second-hottest state, with an average annual temperature of 70.2°F (21.2°C). Unlike most southern states, its tropical climate keeps conditions warm without dramatic swings between summer and winter.

Trade winds and ocean influence help regulate temperatures, so even when it’s hot, it often feels more comfortable than in humid mainland regions. Across the islands, elevation creates variation, with cooler air at higher altitudes and warmer coastal communities.

Louisiana combines heat and humidity in a way that defines summer in the southeast. Its average annual temperature sits at 67.2°F (19.6°C), but what really stands out is how often it gets extremely hot.

The state sees about 90 days each year above 90°F (32.2°C). Because of its position along the Gulf of Mexico, humidity levels are high, which can push the heat index up to 120°F (48.9°C).

That makes it a prime example of why measured temperatures alone don’t tell the whole story.

Texas stands out for its sheer scale and its summer extremes. While its average annual temperature is 65.8°F (18.8°C), it records the highest average summer temperature in the country at 81.3°F (27.4°C).

The state’s geography explains a lot. Flat landscapes, especially along the Gulf Coast and into the Chihuahuan Desert, allow heat to build with little obstruction. In many parts, high temperatures regularly surpass 100°F (37.8°C), especially in July and August.

Georgia ties for the fifth-hottest state with an average annual temperature of 64.3°F (17.9°C). Its climate fits the classic southeastern pattern: hot, humid summers and relatively mild winters.

Humidity plays a major role here. Even when temperatures are slightly lower than in places like Texas or Arizona, the added moisture in the air makes summer feel more intense. Rainfall is also more common, especially during the warmer months.

Mississippi shares the same average annual temperature as Georgia at 64.3°F (17.9°C), placing it in a tie for fifth. Like its neighbor, it experiences long stretches of humid summer weather.

The combination of heat and moisture defines daily life during peak summer. High humidity limits nighttime cooling, which means temperatures stay warm even after sunset.

Alabama continues the trend across the southeast, with hot summers, mild winters, and steady humidity. Its climate is shaped by proximity to the Gulf and inland weather patterns that trap warm air.

Summer heat builds steadily from June into August, with frequent thunderstorms adding moisture to the air. Compared to drier regions, that humidity creates a stronger sense of heat.

South Carolina shares many of the same characteristics as other southern Atlantic states. A humid subtropical climate brings high temperatures and sticky summer conditions.

Coastal areas feel the influence of the Atlantic Ocean, while inland regions can heat up more quickly. Across the state, the balance of sun, humidity, and rainfall shapes a long hot season.

Arkansas sits at the edge of the southeast and central U.S., blending humid conditions with inland heat. Summers are consistently hot, with temperatures often climbing into the 90s.

Rainfall adds to the humidity, especially in late spring and early summer. Compared to more arid states, that moisture changes how the heat feels day to day.

Arizona rounds out the list with a very different kind of heat. Unlike the humid southeast, this southwestern state is known for its dry climate and extreme temperatures.

Elevation creates major differences across the state. Cities like Phoenix see average summer highs between 104.2 and 106.5°F (40.1 to 41.4°C), while higher-elevation areas like Flagstaff stay much cooler. This contrast shows how geography shapes temperature across one state.

Data from the National Oceanic and Atmospheric Administration (NOAA) shows extremes ranging from frigid winters in places like New Hampshire to intense summer heat in the desert southwest, including California’s Death Valley, which averages 117.4°F (47.4°C) in July.

That range highlights just how diverse weather in America can be.

Lists like this offer a way to compare climates—from humid coastal regions to dry desert landscapes—and to see how factors like elevation, rainfall, and geography influence temperature across the world and within one country.

We created this article in conjunction with AI technology, then made sure it was fact-checked and edited by a HowStuffWorks editor.