Alaska has the highest average relative humidity of any U.S. state, at roughly 77%. But if you’re asking which state actually feels the most humid, the answer is Florida. The distinction comes down to how humidity is measured, and it matters more than most people realize.
Why Alaska Tops the Humidity Charts
Relative humidity is a percentage that describes how much moisture the air is holding compared to the maximum it could hold at that temperature. Cold air holds far less moisture than warm air, so it takes only a tiny amount of water vapor to saturate it. Alaska’s cool temperatures mean the air reaches high saturation levels easily, pushing the state’s average relative humidity to 77%.
Several Alaskan stations illustrate this clearly. St. Paul Island averages 84% afternoon relative humidity year-round. Barrow sits at 80%, and Yakutat at 77%. These are some of the highest readings at any weather station in the country, yet stepping outside in Barrow in August feels nothing like stepping outside in Miami.
Florida Feels the Most Humid
Florida averages about 74% relative humidity, second to Alaska on paper. But the moisture you actually feel on your skin depends on a different measurement: the dew point. The dew point is the temperature at which water vapor in the air starts condensing into liquid. The higher the dew point, the more total moisture is packed into the air, and the harder it is for your sweat to evaporate. That’s what creates the sticky, oppressive feeling most people mean when they say “humid.”
A 50°F day with 100% relative humidity contains far less actual moisture than a 90°F day with 50% relative humidity. The warmer day, with its higher dew point, feels dramatically muggier. Florida’s combination of high temperatures and high moisture content produces some of the highest dew points in the country. Tampa recorded a dew point of 86°F in August 2000, and Fort Myers has hit 84°F multiple times. Dew points above 70°F are considered uncomfortable, and above 75°F most people find conditions oppressive. Florida regularly exceeds both thresholds from June through September.
Other States With Extreme Humidity
The Gulf Coast states cluster near the top of any humidity ranking, regardless of which metric you use. Louisiana, Mississippi, Alabama, and Texas all experience sustained high dew points during summer, driven largely by moisture streaming northward from the Gulf of Mexico. Winds transport enormous volumes of water vapor from the warm Gulf waters inland, where it settles over the southeastern states. This moisture advection is the primary engine behind the region’s legendary summer mugginess.
Hawaii also ranks consistently high. Its tropical location and surrounding ocean keep both relative humidity and dew points elevated year-round, though ocean breezes moderate how oppressive it feels compared to the stagnant air common in Gulf Coast cities. Washington state has pockets of very high relative humidity as well. The Stampede Pass station averages 78% annually, and coastal areas like Olympia average 64%, though the Pacific Northwest’s cooler temperatures keep dew points low enough that it rarely feels muggy.
Why the Measurement Matters
Relative humidity is the number you’ll see most often in weather reports, but it can be genuinely misleading. A desert morning can register 90% relative humidity when temperatures are low, then drop to 15% by afternoon as the air warms, even though the actual amount of moisture hasn’t changed. The air’s capacity expanded with the heat, making the same moisture a smaller percentage of the total.
Dew point, by contrast, stays stable throughout the day regardless of temperature swings. It’s a direct measure of how much water vapor is in the air. When meteorologists want to communicate how a day will actually feel, dew point is the more reliable number. A dew point of 55°F feels comfortable. At 65°F, you’ll start to notice the humidity. At 75°F and above, the air feels thick and sweat doesn’t evaporate well, which is why your body struggles to cool itself.
This cooling failure is what makes high humidity dangerous during heat waves. When both temperature and dew point are high, the heat index (what the temperature “feels like”) climbs rapidly. The National Weather Service considers a heat index of 105°F dangerous for heat-related illness. High dew points are a major factor in pushing the heat index into that range, even when the actual air temperature is lower.
Living With High Humidity
If you live in one of the most humid states, indoor moisture control is a year-round concern. The EPA recommends keeping indoor humidity between 30% and 50%. Above that range, you’re creating conditions that encourage mold growth, dust mites, and musty odors. A simple humidity gauge from a hardware store can tell you where your home sits.
Air conditioning is the most effective tool for managing indoor humidity in warm, humid climates because it cools the air and removes moisture simultaneously. In cooler humid areas like the Pacific Northwest or Alaska, a standalone dehumidifier is often the better choice since you don’t necessarily need to lower the temperature. Ventilation helps too, but only when the outdoor air is drier than the air inside, which is rarely the case during a Florida summer.
The geographic drivers of humidity are worth understanding if you’re considering a move. Proximity to warm bodies of water, especially the Gulf of Mexico, is the single biggest factor. Coastal cities in the Southeast sit directly in the path of moisture-laden air flowing off the Gulf. Inland areas at higher elevations tend to be significantly drier. Even within a single state like Texas, the difference between Houston’s coastal mugginess and El Paso’s desert air is dramatic.