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View Poll Results: ...
Paris 21 60.00%
Christchurch 14 40.00%
Voters: 35. You may not vote on this poll

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Old 04-18-2011, 06:32 AM
 
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Those who voted for Paris obviously never spent much winters up there : sometimes when there are cold spells in January (not every year I agree) and at night, temperatures can plummet as low as -20° C! yes it happens in Paris, from time to time (about every 5 or 6 years). And due to the high humidity, it feels more like -25°C!
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Old 04-18-2011, 12:46 PM
 
Location: motueka nz
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Quote:
Originally Posted by pigeonhole View Post
Those who voted for Paris obviously never spent much winters up there : sometimes when there are cold spells in January (not every year I agree) and at night, temperatures can plummet as low as -20° C! yes it happens in Paris, from time to time (about every 5 or 6 years). And due to the high humidity, it feels more like -25°C!
Is there any index that shows higher humidity increasing the feeling of cold?
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Old 04-19-2011, 04:26 AM
 
Location: The western periphery of Terra Australis
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Originally Posted by Stoney63 View Post
Is there any index that shows higher humidity increasing the feeling of cold?
I've heard that humidity does make a place feel colder as well as hotter, kind of like a reverse heat index, and from personal experience this does SEEM to be the case, although there are other factors like lack of sunshine/wind/precipitation.
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Old 04-19-2011, 09:13 AM
 
Location: Toronto
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Quote:
Originally Posted by Stoney63 View Post
Is there any index that shows higher humidity increasing the feeling of cold?
Quote:
Originally Posted by Trimac20 View Post
I've heard that humidity does make a place feel colder as well as hotter, kind of like a reverse heat index, and from personal experience this does SEEM to be the case, although there are other factors like lack of sunshine/wind/precipitation.
But for all the people who feel the effect of humidity at cool temperatures, I've never seen any type of measuring or quantifying of it the way the wind chills, humidex/heat index have done. I mean those measurements are based on subjective feelings of the human body too, so why not?
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Old 04-19-2011, 11:27 AM
 
Location: motueka nz
504 posts, read 994,837 times
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Quote:
Originally Posted by Trimac20 View Post
I've heard that humidity does make a place feel colder as well as hotter, kind of like a reverse heat index, and from personal experience this does SEEM to be the case, although there are other factors like lack of sunshine/wind/precipitation.
I think the other factors are often overlooked. In different jobs I have done, the higher the humidity (at any temperature) the slower the rate of heat loss.
A reverse heat index would imply that as absolute humidity drops, humidity increases in it's ability to cool. It doesn't make sense to me( unless someone can explain it better)

Quote:
Originally Posted by Stumbler. View Post
But for all the people who feel the effect of humidity at cool temperatures, I've never seen any type of measuring or quantifying of it the way the wind chills, humidex/heat index have done. I mean those measurements are based on subjective feelings of the human body too, so why not?
Is it actually humidity they are feeling though? Subjectivity is fine, but awareness is better in my humble opinion.
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Old 04-19-2011, 12:45 PM
 
Location: Toronto
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Quote:
Originally Posted by Stoney63 View Post
I think the other factors are often overlooked. In different jobs I have done, the higher the humidity (at any temperature) the slower the rate of heat loss.
A reverse heat index would imply that as absolute humidity drops, humidity increases in it's ability to cool. It doesn't make sense to me( unless someone can explain it better)


Is it actually humidity they are feeling though? Subjectivity is fine, but awareness is better in my humble opinion.
Yeah, but I'm thinking that the humidity at low temperatures make it also harder for your body to warm up, right? Just as at high temperatures it makes it harder for your body to cool down. If they can make an index for one, couldn't they do so for the other.

I mean, isn't it like how you get cold fast in wet clothes rather than dry clothes when it's chilly outside (since your body heat goes into warming/evaporating the water around you rather than warming you)? Or how you could easily get hypothermia from staying in water that is even at room temperature.
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Old 04-19-2011, 01:30 PM
 
Location: New York City
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There are 2 factors: the moisture on your skin and moisture in the air. The moisture on your skin, when it evaporates, cools you down. However, when humidity is high, this evaporation is slowed. This is why when it is hot and humid outside, you get very visibly wet. You are perspiring but the moisture is not evaporating fast enough. You end up feeling hot and uncomfortable. When it is hot and dry, you are still perspiring but you don't get wet because the moisture evaporates (and cools your body) so quickly.

How this all applies to cold weather, I am not sure. If your skin is dry, than humidity in the air shouldn't matter. Also, cold air holds a lot less moisture than does warm air. This is why I am a big skeptic of the theory that humidity makes cold temperatures feel colder. I think wind is a much more important factor.
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Old 04-19-2011, 01:41 PM
 
Location: motueka nz
504 posts, read 994,837 times
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Quote:
Originally Posted by Stumbler. View Post
Yeah, but I'm thinking that the humidity at low temperatures make it also harder for your body to warm up, right? Just as at high temperatures it makes it harder for your body to cool down. If they can make an index for one, couldn't they do so for the other.

I mean, isn't it like how you get cold fast in wet clothes rather than dry clothes when it's chilly outside (since your body heat goes into warming/evaporating the water around you rather than warming you)? Or how you could easily get hypothermia from staying in water that is even at room temperature.
I don't think the wet clothes comparison is correct, because it wouldn't be the humidity that made your clothes wet in the first place. Assuming you did have wet clothes, they would dry quicker in dry air than wet air of the same temperature. The wet air slows the rate of heat loss, the same reason sweat becomes less effective at higher humidity. Water molecules conduct on to other water molecules when your in water, so it is a different situation

I think the wetness of humid air could be overvalued. It is 23C and 78% RH inside the house but not visibly wet in any way. At -20C and the same humidity the absolute humidity would be very low.
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Old 04-19-2011, 01:49 PM
 
Location: motueka nz
504 posts, read 994,837 times
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Quote:
Originally Posted by MrMarbles View Post
There are 2 factors: the moisture on your skin and moisture in the air. The moisture on your skin, when it evaporates, cools you down. However, when humidity is high, this evaporation is slowed. This is why when it is hot and humid outside, you get very visibly wet. You are perspiring but the moisture is not evaporating fast enough. You end up feeling hot and uncomfortable. When it is hot and dry, you are still perspiring but you don't get wet because the moisture evaporates (and cools your body) so quickly.

How this all applies to cold weather, I am not sure. If your skin is dry, than humidity in the air shouldn't matter. Also, cold air holds a lot less moisture than does warm air. This is why I am a big skeptic of the theory that humidity makes cold temperatures feel colder. I think wind is a much more important factor.
I couldn't have put it better. Measuring humidity and temps in near/ below freezing conditions have been a part of my employment for long periods. I don't associate high humidity alone, with feeling colder.
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Old 04-20-2011, 03:35 AM
 
Location: The western periphery of Terra Australis
24,682 posts, read 50,873,732 times
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Quote:
Originally Posted by Stumbler. View Post
Yeah, but I'm thinking that the humidity at low temperatures make it also harder for your body to warm up, right? Just as at high temperatures it makes it harder for your body to cool down. If they can make an index for one, couldn't they do so for the other.

I mean, isn't it like how you get cold fast in wet clothes rather than dry clothes when it's chilly outside (since your body heat goes into warming/evaporating the water around you rather than warming you)? Or how you could easily get hypothermia from staying in water that is even at room temperature.
I think you are spot on Stumbler. Ever notice how 'x' water temperature always feels way more extreme than the same air temperature? For example, we can tolerate a 4C air temp with warm clothes quite comfortably, but even in a jacket 4C water temps would be absolutely icy. Likewise, we could tolerate maybe up to 65-70C air temps (dunno if anyone's tried) for a short while, but that hot water that scalds you from out of your tap is only about 45-50C.
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