Alaska leads all 50 states in average relative humidity at roughly 77%, but that number explains only half the picture. Southern states like Florida and Louisiana dominate dew point rankings, which is the metric that determines whether air actually feels sticky and oppressive.
The gap between those two measures matters more than most rankings articles acknowledge. Relative humidity is a percentage of how full the air is relative to its maximum capacity at a given temperature. Dew point is the actual temperature at which air becomes saturated, a direct measure of how much moisture is present. Alaska’s air is cold and nearly saturated, producing a high relative humidity reading while remaining perfectly comfortable to breathe. Florida’s air in August is warm, wet, and genuinely difficult to be outside in.
This guide covers how to read humidity data correctly, the 10 most humid states ranked by relative humidity, which states dominate on dew point, the most humid U.S. cities, how humidity damages homes and affects resale value, the five driest states, summer humidity by state, and what to know before relocating out of a humid market.
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What Is the Most Humid State in the U.S.?
Relative Humidity vs. Dew Point: Two Different Answers to the Same Question
“Most humid state” is actually two different questions with two different answers, depending on which metric you use.
Relative humidity measures moisture as a percentage of the air’s maximum moisture-holding capacity at a given temperature. Cold air holds far less moisture than warm air, so it reaches near-saturation at very low absolute water content. That is why Alaska, despite having very little actual moisture in its air, consistently registers the highest relative humidity in the country.
Dew point measures the temperature at which air becomes fully saturated and condensation forms. It is a direct measure of how much moisture is actually present, independent of air temperature. According to the National Weather Service’s explanation of dew point vs. humidity, a dew point above 65°F feels noticeably muggy, and a dew point above 70°F is classified as oppressive or dangerous for outdoor activity.
For anyone choosing where to live, planning outdoor work, or evaluating a home purchase, dew point is the more useful number. Relative humidity tells you how full the air is. Dew point tells you how much moisture is actually there.
Why Alaska Tops the Relative Humidity Rankings
Alaska’s average relative humidity sits at approximately 74.33% to 77%, depending on the source and measurement methodology used. Its cold, consistently moisture-saturated air keeps that percentage near the top year-round. But Alaska’s annual average dew point hovers well below 50°F, meaning the air feels cool and damp rather than hot and sticky.
The practical implication is straightforward: Alaska is not muggy. Its high relative humidity reading reflects the physics of cold-air saturation, not the kind of oppressive heat-and-moisture combination that defines Florida in July.
The 10 Most Humid States by Relative Humidity (2026 Rankings)
Full Ranked Table: Average Daily and Afternoon Humidity by State
The table below uses average daily relative humidity data. According to World Population Review’s state humidity rankings, Alaska leads all states, followed closely by Louisiana and Mississippi.
| Rank | State | Avg. Relative Humidity |
|---|---|---|
| 1 | Alaska | 74.33% |
| 2 | Louisiana | 74.25% |
| 3 | Mississippi | 72.5% |
| 4 | Michigan | 72.19% |
| 5 | Florida | 72.17% |
| 6 | Minnesota | 71.90% |
| 7 | Hawaii | ~71% |
| 8 | Iowa | ~71% |
| 9 | Alabama | ~70% |
| 10 | Missouri | ~70% |
Based on World Population Review average daily relative humidity data, 2026. Verify current figures before making relocation or financial decisions.
How These Numbers Are Measured (and Why Sources Disagree)
Rankings shift meaningfully depending on whether a source uses daily average readings, morning-only readings, or annual averages. Morning humidity readings are systematically 20 to 30 percentage points higher than afternoon readings on the same day in the same city, because cooler morning temperatures push air closer to saturation.
A 2025 data set circulating on social media, for example, places Alabama first at 77.1%, with Florida second at 74.5% and Louisiana third at 74.0%. World Population Review’s methodology, which uses daily averages across all hours, places Alaska first. Neither source is wrong in isolation. They are measuring different things at different times of day.
This article uses World Population Review’s daily-average methodology because it produces the most stable annual comparisons. When you encounter a conflicting ranking elsewhere, check whether the source used morning, afternoon, or full-day average readings before drawing any conclusions.
The Most Humid States by Dew Point, Where It Actually Feels Muggy
Hawaii: The Only State With a Year-Round Dew Point Above 65°F
Hawaii is the most consistently muggy state when measured by dew point. Dew point data compiled across climate sources puts Hawaii’s average annual dew point at 65.2°F, making it the only U.S. state where annual average conditions cross the National Weather Service threshold for noticeable discomfort. Trade winds moderate the heat somewhat, but the moisture is continuous year-round.
Florida and Louisiana: Highest Summer Absolute Humidity in the Contiguous U.S.
Florida ranks second nationally by annual average dew point at approximately 62.74°F, followed by Louisiana at 58.3°F and Mississippi at 55.8°F. Those annual averages substantially understate summer conditions. During July and August, Florida and Louisiana regularly record dew points above 70°F, the level the National Weather Service classifies as oppressive and heat-stress-inducing.
New Orleans averages a July dew point near 74°F, one of the highest readings of any U.S. city. A 90°F day at 75% relative humidity produces a heat index of approximately 109°F according to NWS heat index data. That gap between actual air temperature and perceived temperature is driven almost entirely by moisture content.
The Gulf Coast States: Mississippi, Alabama, Texas, Georgia
Mississippi, Alabama, Texas, and Georgia all experience sustained summer dew points in the 65°F to 72°F range. The Gulf of Mexico acts as a continuous moisture source during summer months, keeping surface air saturated through the afternoon hours when relative humidity would otherwise fall.
For anyone comparing Gulf Coast states with drier alternatives, dew point data from June through September is far more predictive of day-to-day comfort than annual averages.
Most Humid Cities in the U.S., Where the Numbers Hit Hardest
10 Major U.S. Cities With the Highest Relative Humidity
State averages smooth out significant local variation. Cities near coastlines or major water bodies consistently run higher than their state averages. New Orleans, Jacksonville, Miami, and Tampa appear consistently at the top of city-level humidity rankings in available climate data.
| Rank | City | Avg. Relative Humidity (approx.) |
|---|---|---|
| 1 | New Orleans, LA | ~86% |
| 2 | Jacksonville, FL | ~83% |
| 3 | Houston, TX | ~82% |
| 4 | Tampa, FL | ~80% |
| 5 | Miami, FL | ~79% |
| 6 | Memphis, TN | ~79% |
| 7 | Birmingham, AL | ~78% |
| 8 | Seattle, WA | ~78% |
| 9 | Nashville, TN | ~76% |
| 10 | Louisville, KY | ~75% |
City relative humidity figures are approximate annual averages sourced from available climate data. Figures vary by source and measurement methodology.
Why City Humidity Can Exceed State Averages (Urban Heat Island + Coastal Proximity)
Dense metro areas generate additional heat through paved surfaces, buildings, and concentrated human activity. This urban heat island effect can add 2°F to 5°F to effective local temperatures, which interacts with coastal moisture to push perceived humidity above what state-level averages suggest.
Cities like New Orleans and Miami sit at the intersection of continuous Gulf moisture supply and urban thermal elevation. That combination explains why their humidity readings consistently exceed Louisiana and Florida state averages, even when using identical measurement methodologies.
How Humidity Affects Your Home, Damage, Costs, and What to Watch
Structural Damage: Mold, Wood Rot, and Foundation Moisture
High humidity is not just uncomfortable. It is destructive to residential structures. According to EPA guidance on indoor moisture and mold growth, indoor relative humidity above 60% promotes mold growth within 24 to 48 hours of sustained exposure. Mold remediation costs in humid-climate homes range from a few hundred dollars for surface treatment to tens of thousands for structural infestations.
Wood framing presents a separate concern. Research from the USDA Forest Products Laboratory documents that wood begins absorbing moisture at indoor relative humidity above 70%, and sustained exposure at that level risks structural degradation over time. In coastal Gulf states, attic spaces and crawl spaces frequently exceed those thresholds during summer months without adequate ventilation.
For sellers in humid markets, knowing what not to repair before listing can prevent costly over-improvement on moisture-adjacent issues that buyers will discount regardless of the repair quality.
HVAC Load and Energy Costs in High-Humidity States
HVAC systems in high-humidity markets carry a dual burden: cooling air temperature and removing moisture from it. Dehumidification requires additional energy beyond standard cooling, and systems in humid climates cycle more frequently and wear faster than those in dry climates.
U.S. Energy Information Administration household energy consumption data shows that Louisiana and Florida homes consume significantly more electricity per household than the national average, with cooling accounting for a disproportionate share. Buyers in these states should budget for HVAC inspection as a standard pre-purchase step, not an optional add-on.
What High Humidity Means for Your Home’s Resale Value
Moisture intrusion and mold are among the most commonly disclosed material defects in Florida home inspections, according to Florida Realtors guidance on seller disclosures. Homes with visible moisture damage, persistent mold odor, or inadequate HVAC capacity typically sell at a discount relative to comparable properties without those issues.
Sellers who invest in home improvements that add value before listing in humid markets should prioritize moisture mitigation, proper attic ventilation, and HVAC servicing ahead of cosmetic upgrades. A dehumidified crawl space and a recently serviced air handler are more compelling to financed buyers than fresh paint over a poorly ventilated bathroom.
What Are the Least Humid States? (Top 5 Breakdown)
Nevada, Arizona, New Mexico: The Driest Contiguous States
The five least humid states by average relative humidity are Nevada, Arizona, New Mexico, Utah, and Colorado. Nevada and Arizona average 38% to 42% relative humidity annually, making them the driest states in the contiguous U.S. by this measure.
| Rank | State | Avg. Relative Humidity |
|---|---|---|
| 1 | Nevada | ~38% |
| 2 | Arizona | ~38% to 42% |
| 3 | New Mexico | ~45% |
| 4 | Utah | ~47% |
| 5 | Colorado | ~49% |
Based on available climate data. Figures vary seasonally and by measurement period.
That dryness is not constant. The desert Southwest experiences a summer monsoon season from July through September, during which afternoon relative humidity can spike from roughly 25% to 55% in a matter of days. NOAA climate data for the Southwest documents this pattern clearly: “dry” in Nevada or Arizona is a seasonal description, not a permanent condition.
How Low Humidity Creates Its Own Health and Home Risks
Sustained relative humidity below 30% causes its own set of problems. Wood in furniture and structural framing shrinks and cracks at persistently low humidity levels, a process the USDA Forest Products Laboratory has documented extensively. Respiratory irritation, nosebleeds, and aggravated sinus conditions are common complaints among people who relocate from humid climates to the desert Southwest.
Indoor humidity control through humidifiers is as common a household tool in Nevada and Arizona as dehumidifiers are in Florida and Louisiana.
Summer Humidity Rankings, Which States Feel Worst June Through August?
The Gulf States in Summer: Dew Points Above 70°F Are Common
Summer is when the gap between Alaska and the Gulf Coast states becomes most dramatic. Alaska cools further, while Florida, Louisiana, Mississippi, Alabama, and Georgia reach peak absolute moisture levels. According to Aprilaire’s summer humidity data by state, Florida reports a summer average relative humidity of approximately 74%, one of the highest in the contiguous U.S.
Dew points tell the more complete story. New Orleans averages a July dew point near 74°F. Jacksonville, Tampa, and Miami typically run 70°F to 73°F dew points through July and August. The Gulf of Mexico supplies warm, moisture-laden air continuously during these months, and afternoon temperatures amplify the heat stress those dew points produce.
The Florida Climate Center at Florida State University documents Florida’s seasonal humidity patterns in detail, confirming that peak uncomfortable conditions concentrate in June through September and that no region of Florida escapes summer humidity entirely.
Why “Feels Like” Temperature Diverges Most in Summer
Heat index, the “feels like” temperature reported in weather applications, calculates the combined effect of air temperature and relative humidity on human thermal comfort. A 90°F day at 75% relative humidity produces a heat index of approximately 109°F according to NWS heat index tables. At 90°F and 90% relative humidity, that figure exceeds 120°F.
The divergence between actual and perceived temperature is largest when both temperature and absolute moisture are simultaneously elevated. That combination is most common from June through August across the Gulf states, which is why summer is when relocation searches from Florida and Louisiana spike most sharply.
Should You Move Away From a Humid State? What to Know Before Relocating
Health Considerations: Respiratory Conditions and Heat Stress
Humidity exacerbates several common respiratory conditions. The American Lung Association notes that sustained indoor humidity above 50% increases mold and dust mite populations, both of which are significant asthma triggers. Outdoor heat stress risk rises sharply when high dew points combine with elevated temperatures, because the body’s primary cooling mechanism (sweat evaporation) slows as air approaches saturation.
Individuals with asthma, COPD, or cardiovascular conditions should factor dew point data specifically into any relocation decision. Moving to a state where summer dew points remain below 60°F can produce measurable improvements in respiratory symptoms within weeks of arrival.
Climate Comfort vs. Cost of Living: The Real Tradeoff
Dry states are not automatically affordable. Nevada and Arizona have absorbed significant relocation pressure over the past decade, and home prices in Las Vegas and Phoenix reflect that demand. Understanding how much house you can afford when relocating matters as much as knowing where you want to end up, because leaving a high-humidity market does not guarantee lower housing costs.
The tradeoff is real: states with low humidity tend to have lower utility costs from reduced HVAC demand, but their most livable metros often carry higher purchase prices than the humid-climate markets people are leaving.
Selling Your Home in a Humid Market Before You Move
Homes in humid climates with moisture damage, aging HVAC systems, or inadequate attic ventilation carry inspection risk that can derail traditional sales. Buyers using financed offers bring appraisal and inspection contingencies, and moisture findings are among the most common reasons homes sit unsold for months in Gulf states.
Sellers who price accurately but cannot control inspection outcomes often find the cash-offer route faster and more predictable than the traditional listing process.
Common Mistakes People Make When Reading Humidity Data
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Treating relative humidity as the only metric. Relative humidity is a ratio, not an absolute moisture measure. Alaska’s 77% relative humidity and Florida’s 72% relative humidity describe very different air conditions because the temperatures are entirely different. Dew point is the correct measure for comparing actual moisture content across climates with different temperature ranges.
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Assuming Alaska is muggy. Alaska’s dew point sits well below 50°F year-round despite its top-ranked relative humidity. The air is cool and damp, not oppressively wet. According to NOAA’s climate measurement guidance, relative humidity reflects the ratio of current moisture to the maximum possible moisture at a given temperature, which is heavily influenced by temperature itself. High relative humidity in a cold climate is a physics outcome, not a comfort problem.
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Comparing annual averages to summer peaks. A state’s annual average relative humidity may look moderate while its summer conditions are extreme. Arizona’s annual average sits near 38%, but July monsoon afternoons regularly push humidity to 55% or higher. Florida’s annual average of 72% understates August conditions, when morning humidity frequently exceeds 90%.
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Ignoring the time of day. Morning humidity readings are consistently 20 to 30 percentage points higher than afternoon readings in the same location. Two sources publishing different rankings for the same state may simply be measuring at different times of day, not reporting contradictory data.
If You’re Selling in a Humid State Before You Move
If you’re weighing a move away from a humid climate, the friction usually isn’t finding where to go. It’s selling where you are. Listing in Florida, Louisiana, or Mississippi means disclosing moisture history, fielding financed buyers who walk over inspection findings, and waiting 60 to 90 days for a traditional close.
iBuyer.com connects you with multiple vetted cash buyers who compete for your property, so you compare real offers and choose your own closing date, typically within 7 to 30 days. You skip the open houses, the inspection renegotiations, and the timeline uncertainty that makes relocation stressful. [Get competing cash offers on your home now.]
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Frequently Asked Questions
The 10 most humid states by average relative humidity are Alaska, Louisiana, Mississippi, Michigan, Florida, Minnesota, Hawaii, Iowa, Alabama, and Missouri. Rankings vary slightly by source depending on whether daily average, morning, or afternoon readings are used. Alaska consistently leads on relative humidity, though Southern states lead on dew point, which is the better measure of how muggy conditions actually feel.
Florida and Louisiana have the worst humidity in terms of how it feels, recording the highest summer dew points in the contiguous U.S. Alaska leads all states in relative humidity at roughly 77%, but its cold temperatures keep dew points low, so the air does not feel sticky. Florida and Louisiana regularly see July dew points above 70°F, which the National Weather Service classifies as oppressive.
Alaska ranks first in relative humidity because cold air reaches its moisture saturation point at much lower absolute water content than warm air. Relative humidity measures how full the air is relative to its maximum capacity, not how much total moisture it contains. Alaska’s air is cold and nearly always close to saturation, producing roughly 77% relative humidity, while its dew points remain low and the air feels comfortable.
Relative humidity is the percentage of maximum moisture air can hold at a given temperature; dew point is the actual temperature at which air becomes saturated, a direct measure of moisture content. Dew point is more useful for assessing comfort: above 65°F feels noticeably muggy, above 70°F feels oppressive. Relative humidity changes with temperature even when actual moisture stays constant, which is why it can mislead when comparing states with very different climates.
The five least humid states by average relative humidity are Nevada, Arizona, New Mexico, Utah, and Colorado. Nevada and Arizona average 38% to 42% relative humidity annually, but both experience significant humidity spikes during the summer monsoon season from July through September. Low humidity below 30% carries its own risks, including respiratory irritation and wood shrinkage in home structures.
Florida is not the most humid state by relative humidity. Alaska ranks first, while Florida ranks fifth nationally at approximately 72.17%. However, Florida’s combination of high temperatures and high moisture content produces summer conditions far more oppressive than Alaska’s damp but cold air, making Florida one of the most uncomfortable states when measured by the dew point standard.
Indoor relative humidity above 60% promotes mold growth within 24 to 48 hours, and wood framing begins absorbing moisture at levels above 70% relative humidity, risking structural degradation over time. In high-humidity states, HVAC systems work harder and cost more to operate. Sellers in humid markets should address moisture damage and ensure proper ventilation before listing the property.
A dew point above 65°F feels noticeably uncomfortable; above 70°F is classified as oppressive by the National Weather Service. Below 55°F, most people find outdoor conditions comfortable regardless of relative humidity. Hawaii is the only U.S. state where the annual average dew point consistently exceeds 65°F, making it the most consistently muggy state year-round by this measure.
Florida, Louisiana, Mississippi, Alabama, and Georgia record the highest humidity levels during summer months, with dew points regularly exceeding 70°F. New Orleans averages a July dew point near 74°F, one of the highest of any U.S. city. Summer relative humidity in these states typically ranges from 74% to 80% during morning hours, before afternoon heating temporarily lowers the ratio.
High ambient humidity can reduce resale value by increasing the risk of mold, wood rot, and HVAC deficiencies that buyers negotiate down or walk away from entirely. In Florida, moisture intrusion and mold are among the most commonly disclosed material defects in home sales. Homes showing signs of moisture damage typically sell at a discount relative to comparable properties in the same market without those issues.
No U.S. state maintains 70°F temperatures year-round, but coastal California and Hawaii come closest to consistent mild conditions. San Diego averages 57°F in January and 76°F in August, the narrowest temperature band of any major contiguous U.S. city. Hawaii is warmer year-round, averaging 75°F to 85°F, but carries significantly higher humidity than coastal California.
High humidity, particularly dew points above 70°F, increases heat stress risk, worsens asthma and COPD symptoms, and promotes airborne mold growth that triggers respiratory reactions. The American Lung Association links sustained indoor humidity above 50% to elevated mold and dust mite populations, both common asthma triggers. Outdoor heat stress risk rises sharply when high temperatures combine with high moisture content because the body cannot cool efficiently through sweat evaporation.
The human body acclimates partially to humidity over 10 to 14 days, improving sweat efficiency and reducing perceived discomfort, but full physiological adaptation is not possible. Heat acclimatization studies show cardiovascular and thermoregulatory improvements after one to two weeks of heat-humid exposure. Individuals with respiratory conditions, the elderly, and young children remain at elevated risk regardless of how long they have lived in a humid climate.
Reilly Dzurick is a licensed real estate agent with over six years of experience and a member of the iBuyer.com Market Insights Team, covering national trends in home selling and the evolving iBuyer landscape. Her firsthand experience working with buyers and sellers gives her a practical perspective on how these platforms impact real homeowners. She holds a degree in Public Relations, Advertising, and Applied Communication.
