U.S. CitiesCity-Data Forum Index
Go Back   City-Data Forum > General Forums > Weather
 [Register]
Please register to participate in our discussions with 1.5 million other members - it's free and quick! Some forums can only be seen by registered members. After you create your account, you'll be able to customize options and access all our 15,000 new posts/day with fewer ads.
Jump to a detailed profile or search
site with Google Custom Search

Search Forums  (Advanced)
Business Search - 14 Million verified businesses
Search for:  near: 
 
 
Old 08-07-2011, 04:54 PM
 
Location: San Luis | Argentina
45 posts, read 42,290 times
Reputation: 45

Advertisements

USA TODAY.

The amount of humidity in the air by itself doesn't make any difference in how cold the air "feels." Sometimes you will hear that the water vapor in the air carries heat away, cooling you faster. At first glance that might seem to make sense because most people have heard of victims of boating accidents dying because they weren't pulled from chilly water before dying of hypothermia -- a cooling of the body's core temperature. In these cases the water does quickly carry heat away from the body and people with no protection can die quickly in 40-degree water. But, even on the most humid of days, especially when the air is chilly, the percentage of water molecules in the air as water vapor is very small. Even if water molecules did carry heat away from your body, there are too few to noticeably cool you. Also, it turns out that water vapor molecules are no better at conducting heat than the nitrogen and oxygen molecules that make up most of the air.
What I have to say here is based on the "Water Vapor Mysticism" chapter in a delightful book, What Light Through Yonder Window Breaks: More Experiments in Atmospheric Physics by Craig F. Bohren, published by John Wiley & Sons, Inc. in 1991. In it, he not only gives the theoretical arguments in the paragraph above, but also describes some simple, home experiments to show things don't cool faster in cool but humid air than in cool but dry air.
Why do people think wet cold is more uncomfortable than dry cold? Bohren's answer makes sense to me. Humid places are often cloudy. A cold, sunny day doesn't feel as chilly as a cold, cloudy day because even as the air is cooling us, direct sunlight is warming us. The USATODAY.com
Quick reply to this message

 
Old 08-07-2011, 05:20 PM
 
Location: Destrehan, Louisiana
2,192 posts, read 3,729,466 times
Reputation: 3493
Quote:
Originally Posted by Tequeño View Post
USA TODAY.

The amount of humidity in the air by itself doesn't make any difference in how cold the air "feels." Sometimes you will hear that the water vapor in the air carries heat away, cooling you faster. At first glance that might seem to make sense because most people have heard of victims of boating accidents dying because they weren't pulled from chilly water before dying of hypothermia -- a cooling of the body's core temperature. In these cases the water does quickly carry heat away from the body and people with no protection can die quickly in 40-degree water. But, even on the most humid of days, especially when the air is chilly, the percentage of water molecules in the air as water vapor is very small. Even if water molecules did carry heat away from your body, there are too few to noticeably cool you. Also, it turns out that water vapor molecules are no better at conducting heat than the nitrogen and oxygen molecules that make up most of the air.
What I have to say here is based on the "Water Vapor Mysticism" chapter in a delightful book, What Light Through Yonder Window Breaks: More Experiments in Atmospheric Physics by Craig F. Bohren, published by John Wiley & Sons, Inc. in 1991. In it, he not only gives the theoretical arguments in the paragraph above, but also describes some simple, home experiments to show things don't cool faster in cool but humid air than in cool but dry air.
Why do people think wet cold is more uncomfortable than dry cold? Bohren's answer makes sense to me. Humid places are often cloudy. A cold, sunny day doesn't feel as chilly as a cold, cloudy day because even as the air is cooling us, direct sunlight is warming us. The USATODAY.com

People who step off an plain from California to New Orleans will beg to differ with ya.

busta
Quick reply to this message
 
Old 08-07-2011, 06:24 PM
 
Location: Connecticut
662 posts, read 389,849 times
Reputation: 558
Why then did -5F in upstate NY feel the same as 25F did in CT just 1 week apart. In both cases there was no windchill and the sky was clear. Additionally i didn't do anything (exercise, drink hot water, etc) that would drastically alter my core temp.

Anyone?
Quick reply to this message
 
Old 08-07-2011, 06:30 PM
 
Location: Land Of Moose, Blueberries, and Chickadees
10,263 posts, read 5,599,966 times
Reputation: 12998
Hmm. I would like this to be true but have to agree with the above poster.

In Florida, the temps may be 89 degrees, same as you might find in sunny California, but I guarantee you that you're going to feel a whole lot hotter in FL.

So, does the reverse hold true for cold? Well, in eastern WA it's very dry. In western WA while not extremely humid, is more humid than eastern WA. In eastern WA we could get away with a long sleeve shirt and sweatshirt and jeans in the winter. In western WA we were bundled up, freezing, the cold going to the bone, it felt like. Same temps.

I'm not here to argue with a scientist, I go only on what I actually feel because facts schmacts, doesn't matter if I feel colder.
Quick reply to this message
 
Old 08-07-2011, 11:20 PM
 
645 posts, read 614,853 times
Reputation: 1714
My first year out of the Marine Corps saw huge changes for me. Immediately out of the Suck, I landed an average job, but I couldn’t afford reliable transportation. By the way, this was 1986. To make a long story short, which I’m bad at doing, I continued my job search, and at the end of the first year, I landed a job in a factory, where I doubled my wage.

The new job was further away, and I went through a lot of cars. I also had a girlfriend, and I made significantly more money than her, so we largely depended on my income alone. Hence, she got a newer car, and I soldiered on with an old wreck that was the same age as me. The car died. I didn’t have the time to change engines and all that folly, so I just broke down and bought a brand new motorcycle.

In the second full year out of the Corps, I rode motorcycle 25 miles each way to work. I did this year round. There were days when it was –05 Fahrenheit. This was my experience. I would rather ride a motorcycle in 20-degree weather in my home state because 20-degree weather is typically very dry. A lot of people complain about chapped skin and lips when the weather’s like this. I favored dry 20 degree-days over 35 – 40 degrees accompanied by very damp weather. The reason was simple, the cold dry air did not cut through my leather in the same fashion that the warmer, but still cold damp air did. I know that defies logic, but the problem is, once you understand how the human body perceives relative temperature, you’ll understand completely why humid weather always feels different than dry weather. For example

Humid cold/hot weather will always feel colder/hotter
Dry cold/hot weather will always feel warmer/cooler

Get the idea? I hope this helped.
Quick reply to this message
 
Old 08-08-2011, 03:02 AM
 
Location: Buxton, England
7,032 posts, read 4,030,998 times
Reputation: 3371
From my experiences this winter the coldest I felt was when it was humid and damp with temps above freezing.

I coped with the cold better when it was well below freezing with low relative humidity as well, even at night (with no sun to make it feel warmer).

Reason? Because when the air is saturated, it is more conductive against my skin. In the cold, at high humidity, I can feel the water particles against my skin and I lose my body heat into the air much quicker.
Quick reply to this message
 
Old 08-08-2011, 05:51 AM
 
Location: Perth, Western Australia
9,598 posts, read 15,601,695 times
Reputation: 3250
^^ yes, they are ignoring the factor of condensation.

It's like calling BS on someone getting colder because it started to rain and they got wet.
100% humidity without rain isn't nearly as bad as getting soaked in rain, but it is noticeable.
Even above 85% you can find microclimates cold enough there is condensation.

I would say for humidity at 75% and below, I agree with the original point.
Quick reply to this message
 
Old 08-08-2011, 06:10 AM
 
Location: San Luis | Argentina
45 posts, read 42,290 times
Reputation: 45
Quote:
Originally Posted by Weatherfan2 View Post
From my experiences this winter the coldest I felt was when it was humid and damp with temps above freezing.

I coped with the cold better when it was well below freezing with low relative humidity as well, even at night (with no sun to make it feel warmer).

Reason? Because when the air is saturated, it is more conductive against my skin. In the cold, at high humidity, I can feel the water particles against my skin and I lose my body heat into the air much quicker.
thats just your opinion, not scientific truth.
Quick reply to this message
 
Old 08-08-2011, 06:17 AM
 
Location: Buxton, England
7,032 posts, read 4,030,998 times
Reputation: 3371
Quote:
Originally Posted by Tequeño View Post
thats just your opinion, not scientific truth.
False.

When I feel myself getting colder quicker in damp cold weather, it isn't my "opinion", it is what is happening. My body loses heat faster in those conditions. Then it takes longer to warm up again. I think I KNOW how cold/warm my body is.
Quick reply to this message
 
Old 08-08-2011, 06:29 AM
 
Location: Perth, Western Australia
9,598 posts, read 15,601,695 times
Reputation: 3250
Quote:
Originally Posted by Tequeño View Post
thats just your opinion, not scientific truth.
Go stand outside when it's 4 C and dry and wait for it to be 4 C and raining.
If you do not feel colder as you get wet, I will be very impressed.
Quick reply to this message
Please register to post and access all features of our very popular forum. It is free and quick. Over $68,000 in prizes has already been given out to active posters on our forum. Additional giveaways are planned.

Detailed information about all U.S. cities, counties, and zip codes on our site: City-data.com.


 

Quick Reply
Message:
Over $84,000 in prizes was already given out to active posters on our forum and additional giveaways are planned!

Go Back   City-Data Forum > General Forums > Weather

All times are GMT -6.

© 2005-2014, Advameg, Inc.

City-Data.com - Archive 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25 - Top