When you think of sticky, humid places in America, Florida probably springs to mind first. Those sweltering summer days where your clothes stick to your skin and your hair refuses to cooperate seem like they couldn’t possibly be worse anywhere else. But surprisingly, Florida doesn’t actually claim the title of America’s most humid state. The real champion might shock you—and completely change how you think about humidity altogether.
Alaska: America’s Unexpected Humidity Champion
When most people think of humidity in the U.S., states like Florida, Louisiana, or Mississippi come to mind—sweltering, sticky climates where the air feels thick enough to swim through. However, the title of most humid state in America doesn’t belong to any of these southern hotspots. Surprisingly, it goes to Alaska, a state more commonly associated with glaciers and frigid winters than oppressive mugginess 146.
Alaska’s average relative humidity (RH) of 77.1% surpasses Florida’s 74.5% and Louisiana’s 74%, making it the undisputed leader in humidity 24. But how does a state known for its cold climate out-humidify the tropical South? The answer lies in the science of relative humidity—a measure of how saturated the air is with water vapor compared to its maximum capacity at a given temperature.
Cold air holds less moisture than warm air, so even a small amount of water vapor can push relative humidity to high percentages in cooler climates. While Alaska’s absolute humidity (actual moisture content) is lower than Florida’s, its colder temperatures mean the air reaches saturation more easily, resulting in higher RH values 17. For example, a 40°F day in Alaska with 70% RH feels damp and chilly, whereas a 90°F day in Florida at 70% RH feels suffocating—but the latter actually has far more moisture in the air.
Many assume humidity is solely a warm-weather problem, but Alaska’s ranking challenges that notion. States like Michigan, Indiana, and Vermont also appear in the top 10 most humid states, proving that cold regions can be just as “humid” in terms of relative measurements 26. However, the perceived discomfort differs:
Alaska’s humidity is often accompanied by mild summers (55–70°F), so it rarely feels oppressive 4.
Southern states like Florida and Louisiana combine high RH with scorching heat, creating a “feels-like” temperature far above the actual thermometer reading 59.
While Alaska wins statistically, the Gulf Coast states dominate when it comes to unbearable mugginess. Cities like Lake Charles, Louisiana (90% RH), and Jackson, Mississippi (90% RH) endure some of the highest dew points in the nation—a metric that better reflects how sticky the air feels 59. Dew point measures the temperature at which air becomes saturated, and values above 65°F are considered uncomfortable. In these regions, summer dew points often exceed 75°F, making outdoor activities feel exhausting 10.
Humidity levels are climbing nationwide due to global warming. Warmer air holds more moisture, and rising ocean temperatures (particularly in the Gulf of Mexico) are pumping additional water vapor into the atmosphere 10. This trend suggests that while Alaska may retain its high RH crown, southern states will likely face even more extreme “feels-like” conditions in the future.
Alaska’s status as the most humid state is a fascinating quirk of meteorology, but it’s the Gulf Coast and Southeastern states that deliver the most oppressive humidity experiences. For those seeking relief, the driest states—Arizona (40.4% RH) and Nevada (38.3% RH)—offer a stark contrast 36. Whether you’re bundling up in Anchorage or sweating in Miami, humidity’s impact is undeniable—and understanding the difference between relative and absolute measures is key to decoding America’s moisture map.
