dew point

See synonyms for dew point on Thesaurus.com

noun

the temperature to which air must be cooled, at a given pressure and water-vapor content, for it to reach saturation; the temperature at which dew begins to form.

Compare Meanings

Click for a side-by-side comparison of meanings. Use the word comparison feature to learn the differences between similar and commonly confused words.

Origin of dew point

First recorded in 1825–35

Also called dew-point temperature.

Compare absolute humidity, mixing ratio, relative humidity, specific humidity.

Words Nearby dew point

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use dew point in a sentence

Humidity levels remain the same with dew points in the mid-70s or so.
D.C.-area forecast: More days of hit-or-miss strong storms, with patchy flash flooding possible | A. Camden Walker | August 27, 2021 | Washington Post
We may have dew points heading back down into the comfortable 50s.
D.C.-area forecast: Increasingly comfortable as we head into the weekend | A. Camden Walker | July 30, 2021 | Washington Post
The dew point of 49 degrees that was recorded in the middle of the day is something we might expect about 1 percent of the time.
PM Update: Delightful low-humidity weather continues through Friday | Ian Livingston | July 22, 2021 | Washington Post
Humidity remains fairly high with dew points in the upper 60s to near 70.
D.C.-area forecast: Consistently hot and humid into this weekend; storms possible today | Dan Stillman | July 14, 2021 | Washington Post
When combining Tuesday’s air temperature and dew point, our skin can’t self-cool as easily, so the apparent “heat index” temperature may feel about 100 degrees in a few locations.
D.C.-area forecast: Turning very comfortable for July. Rain chances diminish through the weekend. | A. Camden Walker | July 2, 2021 | Washington Post

Hence the utility of instruments for determining the dew-point.
A Treatise on Meteorological Instruments | Henry Negretti
The temperature at which air is saturated and condensation begins is called the dew point.
General Science | Bertha M. Clark
As soon as a mass of air is cooled to its dew-point, water begins to be precipitated in the form of rain, dew, snow or hail.
Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 3 | Various
This temperature is the dew point of the air after it passes up into the drying chamber above the coils.
Seasoning of Wood | Joseph B. Wagner
Knowing the temperature in the drying room and the dew point, the relative humidity is thus determined.
Seasoning of Wood | Joseph B. Wagner

British Dictionary definitions for dew point

dew point

noun

the temperature at which water vapour in the air becomes saturated and water droplets begin to form

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for dew point

dew point

The temperature at which the water vapor contained in a volume of air at a given atmospheric pressure reaches saturation and condenses to form dew. The dew point varies depending on how much water vapor the air contains, with humid air having a higher dew point than dry air. When large droplets of condensation form, they are deposited onto surfaces as dew. When smaller droplets form, they remain suspended in the air as mist or fog. If the dew point is below the freezing temperature of water (0°C), the water vapor turns directly into frost by sublimation.

Browse