# What Temp Does Water Freeze, in Denver? **URL:** \ **Category:** Factual Questions\ **Created:** [October 22, 2004, 5:03pm UTC](https://boards.straightdope.com/t/what-temp-does-water-freeze-in-denver/270622 "2004-10-22T17:03:36Z")\ **Posts on this page:** 6\ **Page:** 2
**Author:** ![Bill\_Door](https://avatars.discourse-cdn.com/v4/letter/b/50afbb/32.png) [@Bill\_Door](https://boards.straightdope.com/u/Bill_Door)\ **Post date:** [November 19, 2021, 4:11pm UTC](https://boards.straightdope.com/t/what-temp-does-water-freeze-in-denver/270622/21 "2021-11-19T16:11:22Z")
Standing water exposed to the sky can freeze when the air temperature is above 32 degrees Fahrenheit due to radiative cooling. The night sky essentially radiates at the background 2.7 K of space. It has nothing to do with any change in freezing temperature. ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [November 19, 2021, 5:31pm UTC](https://boards.straightdope.com/t/what-temp-does-water-freeze-in-denver/270622/22 "2021-11-19T17:31:19Z")
> [@EmeraldsEclectics](#): > > I can also confirm that in upstate NY, when humidity is high and pressure drops quickly, standing water can easily freeze at 36°. As an Upstater I will argue that standing water does not freeze when the atmospheric temperature is 36° but when the microclime at the surface of the water is at or below 32°. Similarly, snow at 36° is common, but occurs because the temperature of the air at the snow’s origin is 32°, regardless of what your surface thermometer reads. ---
**Author:** ![am77494](https://avatars.discourse-cdn.com/v4/letter/a/d2c977/32.png) [@am77494](https://boards.straightdope.com/u/am77494)\ **Post date:** [November 19, 2021, 5:49pm UTC](https://boards.straightdope.com/t/what-temp-does-water-freeze-in-denver/270622/23 "2021-11-19T17:49:30Z")
Air temperature is not a good measure of water lying on the ground. The temperature is high below ground (think frost line) and keeps pooled water a few degrees above freezing. ---
**Author:** ![AskNott](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/asknott/32/5790_2.png) [@AskNott](https://boards.straightdope.com/u/AskNott)\ **Post date:** [November 20, 2021, 11:28pm UTC](https://boards.straightdope.com/t/what-temp-does-water-freeze-in-denver/270622/24 "2021-11-20T23:28:42Z")
At a greatly reduced pressure, water can actually boil **and** freeze in the same dish. This was demonstrated to me in an 8th grade science class. Mr. King set a glass dish of water in a bell jar and hooked it up to a vacuum pump. After a few minutes, the water was evaporating fast enough to get to a rolling boil. The evaporation removed enough heat that a disc of ice started to grow on top of the boiling water. I’m 72 years old, and I still feel the excitement from that classroom. ---
**Author:** ![Francis\_Vaughan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/francis_vaughan/32/3093_2.png) [@Francis\_Vaughan](https://boards.straightdope.com/u/Francis_Vaughan)\ **Post date:** [November 21, 2021, 2:27am UTC](https://boards.straightdope.com/t/what-temp-does-water-freeze-in-denver/270622/25 "2021-11-21T02:27:13Z")
Making ice in the desert at night has been well known since antiquity. A shallow dish left exposed to a clear night sky and sheltered from wind will freeze even if the average air temperature is above freezing. The local temperature will drop below freezing. One can collect the ice at dawn and keep it in an insulated container. Minimally you have ice for your evening G&T, but potentially for many useful purposes. ---
**Author:** ![nearwildheaven](https://avatars.discourse-cdn.com/v4/letter/n/90db22/32.png) [@nearwildheaven](https://boards.straightdope.com/u/nearwildheaven)\ **Post date:** [November 21, 2021, 7:09am UTC](https://boards.straightdope.com/t/what-temp-does-water-freeze-in-denver/270622/26 "2021-11-21T07:09:04Z")
The boiling point of water lowers by about a degree Celsius for every 1,000 feet of elevation. I lived at 7,000 feet when doing rotations in New Mexico, and spaghetti took FOR-EV-ER to cook, or so it seemed. [Previous page](https://boards.straightdope.com/t/what-temp-does-water-freeze-in-denver/270622.md?page=1)