Dew Point Chart: From Dry to Oppressive
The dew point scale runs from crisp to unbearable in about 25 degrees: below 50°F the air feels dry, at 65°F it turns muggy, and past 75°F it is the stuff of Gulf Coast Augusts. The chart below maps every band.
Dew point is the temperature the air would have to cool to for its moisture to condense, which makes it an absolute moisture reading — unlike relative humidity, it doesn't swing when the temperature changes. That is why one chart can describe the feel of the air in any city, any season, and why the 7 bands below are worth memorizing once and using forever.
Where the air changes character
Chips mark the °F dew points where sticky (60), muggy (65), and oppressive (70) begin. The full chart below adds the 75°F+ miserable band and each row's humidity at 90°F.
The dew point comfort chart
| Dew point (°F) | Band | How it feels | RH at 90°F |
|---|---|---|---|
| 50 or below | Dry | Crisp, dry air — the sky feels transparent and sweat vanishes instantly | 25% or less |
| 50–55 | Comfortable | Pleasant for nearly everyone — the range most people never notice | 25–31% |
| 55–60 | Getting sticky | The first hint of moisture — noticeable on a warm afternoon | 31–37% |
| 60–65 | Sticky | Humid — the air has weight and shade stops helping as much | 37–44% |
| 65–70 | Muggy | Unmistakably tropical — evaporation slows and effort feels harder | 44–52% |
| 70–75 | Oppressive | Thick, heavy air — sweat stops cooling and the heat index climbs fast | 52–62% |
| 75 or above | Miserable | Rainforest air — rare outside the Gulf Coast, and the top of the scale | 62% or more |
Bands follow NWS dew-point comfort guidance. The final column is the relative humidity the same dew point produces at 90°F air temperature, computed with the Magnus saturation-vapor-pressure formula (Alduchov & Eskridge 1996 coefficients: a = 17.625, b = 243.04 °C) — deterministic and reproducible.
The chart: seven bands from dry to miserable
The table above is the whole reference. The first column is the dew point in °F — the number this site's city pages lead with. The band and feel columns translate it into the NWS comfort vocabulary, and the final column shows the relative humidity the same moisture would produce on a 90°F afternoon, computed with the Magnus saturation-vapor-pressure formula.
That last column is the chart's quiet argument. A 70°F dew point on a 90°F day is only about 52% relative humidity — a number that sounds moderate while the air feels like soup. Same air, two very different impressions, which is why the dew point column is the one to trust.
Band by band, up the ladder
Below 50°F, evaporation is instant and the air stays out of your way — desert mornings and crisp fall afternoons live here. From 50 to 55°F is the comfortable zone most of the country enjoys in late spring. The 55–65°F stretch is the transition: first a hint of stickiness, then air with real weight to it by the low 60s.
At 65°F the character changes — this is where "muggy" begins — and each step up compresses comfort further. The 70–75°F band is oppressive, the zone where a summer evening never quite cools off. Past 75°F the chart runs out of polite words: that is rainforest-grade moisture, and outside the Gulf states most US cities never touch it.
"Muggy," defined: the 65–70°F band
Muggy is not slang on this chart — it is the working label for the 65–70°F dew-point band in NWS comfort guidance. The physics underneath it: your skin cools by evaporating sweat, and evaporation runs on the gap between the moisture in your skin's boundary layer and the moisture in the air. As the dew point climbs through the mid-60s, that gap narrows enough that cooling visibly lags on any exertion.
The word earns its precision at night. A 65°F-plus dew point puts a floor under the overnight low — the temperature can't fall much below the dew point without fog and dew forming and the condensation releasing heat — so muggy afternoons roll into warm, thick evenings. A dry 90°F day cools into a pleasant night; a muggy one doesn't.
How dew point feeds the heat index
The "feels like" number on a summer forecast is the NWS heat index, a regression published by Lans Rothfusz in 1990 that combines air temperature with humidity to estimate apparent temperature. Humidity enters that formula as relative humidity, but dew point is what sets it: at a given temperature, the dew point fixes the RH — at 90°F, a 65°F dew point means about 44% RH and a 75°F dew point about 62%.
Reading the two together is simple: temperature says how hot the air is, dew point says how much of your cooling the air has confiscated. The heat index just does that arithmetic formally, which is why two 90°F afternoons can carry heat-index values many degrees apart.
What summer looks like, region by region
NOAA climatology sorts the country cleanly onto the chart. Gulf Coast metros — New Orleans, Houston, Mobile, Tampa — spend midsummer with dew points in the low-to-mid 70s, camped in the oppressive band with excursions past 75°F. The Midwest and East Coast run seasonally muggy, with corn-belt moisture pushing Iowa and Illinois into the low 70s during July humid spells.
The West flips the chart. Before the monsoon arrives, desert Southwest dew points sit in the 30s and 40s even at 105°F air temperatures — bone-dry by the chart's first rows — and the Pacific coast's marine layer holds dew points in the comfortable 50s nearly year-round. The same 90°F afternoon reads as three different climates depending on the row your city occupies.
Reading your city's dew-point page
Every city page on this site leads with the current dew point, the relative humidity, and a comfort verdict drawn from the same thresholds as this chart. The reading to anchor on is the dew point itself: find its row above, and you know how outside feels before you open the door. The RH figure is context, not the verdict — remember the 52%-can-feel-like-soup lesson from the chart's fourth column.
For planning, watch the trend the way you'd watch a barometer. Dew points climb ahead of humid air masses and crash behind cold fronts, so a forecast drop from 70°F to 55°F is the atmosphere promising a different world by morning.
The chart, by the numbers
the dew point where “muggy” officially begins
NOAA / NWS
the oppressive threshold — overnight lows can't fall far below it
NOAA / NWS
relative humidity a 70°F dew point makes at 90°F — soup that sounds moderate
Magnus formula (Alduchov & Eskridge 1996)
the Rothfusz regression behind the NWS heat index
NWS
Check your local dew point
The top rows of the comfort chart are a Gulf Coast summer: NOAA climatology puts midsummer dew points along the Gulf in the low-to-mid 70s — the oppressive band, for weeks at a stretch. These pages show each metro’s live dew point and comfort verdict, or look up any US city on the dew point hub:
- New Orleans, LA dew point — Surrounded by warm Gulf water and wetlands — midsummer dew points sit in the low-to-mid 70s for weeks.
- Houston, TX dew point — Gulf onshore flow keeps its summer air in the oppressive band more often than almost any large US metro.
- Corpus Christi, TX dew point — Right on the Gulf — the sea breeze imports 75°F-class dew points straight off the water.
- Miami, FL dew point — Tropical marine air on three sides; the muggy-to-oppressive bands are its summer baseline.
- Tampa, FL dew point — Bay and Gulf moisture push July dew points into the low-to-mid 70s nearly every afternoon.
- Mobile, AL dew point — One of the wettest, most humid corners of the Gulf Coast — top-of-the-chart summer air.
Frequently asked
- What dew point is considered muggy?
- 65–70°F is the muggy band in NWS comfort guidance. Below 65°F the air is sticky but manageable; at 70°F and above the label shifts to oppressive.
- What does muggy mean?
- Warm, noticeably humid air — on this chart, a dew point of 65–70°F. The physical meaning: enough moisture in the air that evaporative cooling visibly slows, so the air feels thick and effort feels harder.
- Is a dew point of 60 comfortable?
- It's the border. 60°F sits at the top of "getting sticky" and the start of the sticky band — most people notice the humidity on a warm day but few call it bad. By 65°F the consensus flips.
- What is this chart in Celsius?
- The band edges convert to roughly: 50°F = 10°C, 55°F = 13°C, 60°F = 16°C, 65°F = 18°C, 70°F = 21°C, and 75°F = 24°C. So muggy begins near 18°C and oppressive near 21°C dew point.
- Does a high dew point mean rain?
- Not by itself — it means moisture is available, which is fuel rather than a trigger. What a high dew point does promise: if the temperature falls to meet it, the air saturates and fog or dew forms. Rain still needs lift from a front, terrain, or daytime heating.
- What dew point feels oppressive?
- 70°F and above. In that band, sweat largely stops evaporating, overnight temperatures can't fall far below the dew point, and the heat index climbs quickly — on a 90°F afternoon, 70°F of dew point is about 52% relative humidity.
- Why does the chart show RH at 90°F?
- To expose the trap in relative humidity: the same dew point produces wildly different RH numbers at different temperatures. Fixing the temperature at 90°F makes the columns comparable — computed with the Magnus formula (Alduchov & Eskridge 1996 coefficients), so the values are exact and reproducible.