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dew point

noun
  1. 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.
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Origin of dew point

First recorded in 1825–35
Also called dew-point temperature.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for dewpoint

Historical Examples

  • Actually it is full enough of dust-nuclei to outfit a fullgrown fog if the dewpoint should be favorable.

    Reading the Weather

    Thomas Morris Longstreth


British Dictionary definitions for dewpoint

dew point

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

Word Origin and History for dewpoint

n.

1833; see dew + point (n.).

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Online Etymology Dictionary, © 2010 Douglas Harper

dewpoint in Science

dew point

  1. 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.
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The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.