Talk:Dew point

Questions
April 22 2024. How much moisture condenses at dew point? All that is in the air, or just what brings humidity below dew point?

I have two questions / suggestions for extra material.

1. I understand the diagram shows the percentage of water vapour that can be carried as a component of air at a given temperature. But what is it a percentage by? Percentage weight, percentage volume, percentage of moles, something else?


 * I believe (and this is from reading the axis on a Psychrometrics) it is w/w.


 * What is the purpose of the first diagram? It is not really used in the text. - 13:34, 29 January 2009 - 80.165.82.22

2. Are the physiological reasons known why a high dew point is held to be oppressive? Notinasnaid 15:51, 11 November 2005 (UTC)


 * Because a high dew point -> higher wet bulb temperature -> sweat evaporates less -> less cooling from sweat -> body shuts down to prevent overheating and heat stroke. Humans can survive surprisingly high ambient temperatures as long as it is dry.  I recall some army guy got in an oven and cooked himself at something like 120C for 5 minutes and survived by drinking water and sweating like crazy. njh 10:12, 11 January 2006 (UTC)


 * I think this is explained quite well in the article. However, there must be an error in the calculation of relative humidity in the table, since the ranges overlap whereas the temperature ranges does not. - 13:34, 29 January 2009 - 80.165.82.22

will a change in air temperature cause the dew point temperature to change as well? —Preceding unsigned comment added by 216.6.155.118 (talk) 02:22, 4 December 2009 (UTC)

dew points
Actually, the Melbourne FL dew point seems to be called more into question than the ones in the Midwest such as Appleton. So will this continue even with a more reliable source? B137 (talk) 23:05, 29 July 2019 (UTC)


 * Discussions about article content should take place on the article's talk page rather than user talk pages, so I've moved it here. Called into question by whom?  In any case, I removed the entire section as unsourced.  If anyone can find  sources for records, then by all means, include them.  –Deacon Vorbis (carbon &bull; videos) 23:15, 29 July 2019 (UTC)


 * Would these also count as bad sources?

https://www.postcrescent.com/story/news/2019/07/19/wisconsin-heat-appleton-once-recorded-heat-index-148-degrees/1781994001/ https://komonews.com/weather/scotts-weather-blog/debunking-the-its-90-degrees-with-90-humidity-claims-back-east
 * All likely source to the same weather record database. B137 (talk) 23:17, 29 July 2019 (UTC)
 * Also, a would have indicated where this was moved to. B137 (talk) 23:33, 29 July 2019 (UTC)

New dew point record
It looks like the 2003 Saudi Arabia dew point record has been recently broken. The dew point temperature was 97 degrees F which is 2 degrees higher than the record. https://twitter.com/US_Stormwatch/status/1691596872903979036 47.12.180.193 (talk) 23:30, 18 August 2023 (UTC)

Incorrect or misleading Arden Buck equation for dew point
In the section on the Arden Buck equation I believe the wrong equation is being used to calculate dew point. The equation in the article is Td = c*γ/(b-γ), but I believe that is only valid for the three constant version. In the 1981 Buck paper he gives the equation for calculating dew point with the additional d constant as: Td = (d/2) * [b - γ - ((b - γ)2 - 4*c*γ/d)1/2]. I stumbled across this because I wrote some code to convert back and forth between RH and dew point, and I found I was getting different answers depending on which direction the calculation went. Switching to the second equation fixed this issue. Madeemay (talk) 20:01, 29 March 2024 (UTC)


 * In my opinion only the Simple approximation should be included in the page, with one or two sentences point to the more complex ones with references. Johnjbarton (talk) 21:16, 29 March 2024 (UTC)