Dry heat vs humid heat

[lobosrul]

Comparatively, no. I'd accept 87% as an overwhelming majority any day of the week.

I wonder how they define cooling equipment. I don't have refrigerated air, but I do have an evaporative cooler (aka swamp cooler). Which usually works just fine, but then it rained several inches in a day here and then got hot and humid, and it just plain sucked.

Having been born in SE Texas and moved to New Mexico I can decidedly say a dry heat is much easier to tolerate than a humid one. Especially if you can find shade. In fact I'd say until it hits just about 100 here, on a normal dry day 20% humidity, it really doesn't bother me much. I saw heat indexes above 120 degrees in Texas summers when I was a child. That sucked.

 

[ben m]

To make a fair comparison, we should be saying: would you rather be in a heat index of 90 from the humid-end of the scale, or a heat-index of 90 from the dry end of the scale? Would you rather be at 90 degrees, 40% humidity or at 86 degrees, 100% humidity?

I still say dry. By a long shot. Dry heat makes me go "whew! that's hot!" and smile and fan myself and mop my brow. Moist heat, at what I think is the same heat index, makes me want to remove my skin.

Perhaps the scientific difference is this: in a dry heat, a breeze---even a light air, Beaufort 1, barely rustling leaves---genuinely cools down your skin. It brings you down all the way to the wet-bulb temperature, which might well be pretty comfortable. You can fan yourself, you can walk, you can stand in front of a fan. Even if it's only bursts of relief, that can make an unpleasantly hot day fairly tolerable.

In humid air, at the same index, the discomfort is just unrelenting. A breeze helps only a little---the strongest breeze on Earth can only get your skin down to the wet bulb temperature, and the web bulb temperature is "slightly less miserable" rather than "nice day".

 

[Ladewig]

With the death rate in an area with a dry extreme heat being 3 times that of a hot, humid area, I'm not sure how "complicated" it can get.

Complications arise in analyzing the figures by state because we don't know how many +100° days occur in each state. If the average dry/hot day kills two people and the average wet/hot day kills three people and Arizona has five times as many dangerously hot days, then looking only at death rate per capita will be misleading.

Furthermore different states sometimes have very different health profiles. If Arizona is full of retirees, they may have a more difficult time dealing with record heat than younger people. Also, the percentage of homes with air conditioners may be a factor. The ability to leave an un-airconditioned house and go to a mall, theater or casino could also vary dramatically in different states. There are other contributing factors that could skew the results enough to make the conclusion much less clear cut.

.


the grammar error is intentional.

 

[Ziggurat]

A small chalet made of all natural materiels, with ezi-care floors and air conditioning by flo-thru ventilation. Financing by owner.

Not just "natural", but "eco-friendly sustainable materials". Oh, and don't forget "radiant heating".

 

[Dymanic]

With the death rate in an area with a dry extreme heat being 3 times that of a hot, humid area, I'm not sure how "complicated" it can get.

Did you read the article you linked? Say an octogenarian with a heart condition expires on a hot day. Was the cause of death heat with an underlying condition as a contributing factor, or was it heart disease with heat as a contributing factor? A key point that article makes is that if you wanted a definitive answer to that question, the very best approach might not to be to look at the death certificate and read what was entered under "cause of death".

And if it were a simple matter of "extreme dry heat" being clearly the prime culprit, you'd expect the top three states to be California, Arizona, and Nevada, in that order. Missouri wouldn't even be in the top three.

 

[RussDill]

I wonder how they define cooling equipment. I don't have refrigerated air, but I do have an evaporative cooler (aka swamp cooler). Which usually works just fine, but then it rained several inches in a day here and then got hot and humid, and it just plain sucked.

Having been born in SE Texas and moved to New Mexico I can decidedly say a dry heat is much easier to tolerate than a humid one. Especially if you can find shade. In fact I'd say until it hits just about 100 here, on a normal dry day 20% humidity, it really doesn't bother me much. I saw heat indexes above 120 degrees in Texas summers when I was a child. That sucked.

yes, a dry 95 is quite do-able, but I don't think that's what people are looking to compare. I've never experienced a 120 heat index from humidity, but I have 120+ temps, it really eats you up. I know that humidity doesn't slow down your sweating, but I'm curious if dry vs moist has effects on other forms of water loss (directly from tissues underneath the skin as well as respiration).

 

[RussDill]

Did you read the article you linked? Say an octogenarian with a heart condition expires on a hot day. Was the cause of death heat with an underlying condition as a contributing factor, or was it heart disease with heat as a contributing factor? A key point that article makes is that if you wanted a definitive answer to that question, the very best approach might not to be to look at the death certificate and read what was entered under "cause of death".

And if it were a simple matter of "extreme dry heat" being clearly the prime culprit, you'd expect the top three states to be California, Arizona, and Nevada, in that order. Missouri wouldn't even be in the top three.

While I understand your premise, that you'd have to control for the health of the individual, I don't think the majority of California or even a significant fraction lives somewhere with extreme heat. Yes, California has death valley...but no one lives there.

Someone else made the point of the number of days out of the year with extreme heat. I know about Phoenix, usually 100+ days over 100, and many days where it doesn't even drop below 100. But in areas that are hot and humid, is it a constant all summer long thing, or does it come in waves?

 

[Dancing David]

Purposely so. I just wanted to see if people would think past their personal comfort levels to what is actually worse.

Dry heat is worse. That's why you have deserts sand dust bowl fire etc. Dry heat kills.

Humid heat is better. That's why you have jungle Everglades Amazon bayou etc.... Humid heat brings life in over abundance.

Humidity might not be comfortable, but I'll take it any day.

Heat stroke occurs at lower temps in high humidity.

 

[lobosrul]

While I understand your premise, that you'd have to control for the health of the individual, I don't think the majority of California or even a significant fraction lives somewhere with extreme heat. Yes, California has death valley...but no one lives there.

Someone else made the point of the number of days out of the year with extreme heat. I know about Phoenix, usually 100+ days over 100, and many days where it doesn't even drop below 100. But in areas that are hot and humid, is it a constant all summer long thing, or does it come in waves?

Well, Dallas hit 100 degrees 71 times in 2011.

http://dallas.about.com/od/neighbor...-New-Record-For-Triple-Digit-Temperatures.htm

And it can be moderately humid there. I was "lucky" enough to be driving through there that summer. It hit 109 to the NW of Dallas.

 

[TubbaBlubba]

With the death rate in an area with a dry extreme heat being 3 times that of a hot, humid area, I'm not sure how "complicated" it can get.

There can be so many explanations for that. Perhaps the more tolerable dry heat causes people to spend more time outside in dry areas, whereas in humid areas people tend to stay indoors or otherwise shield themselves?

 

[rwguinn]

While I understand your premise, that you'd have to control for the health of the individual, I don't think the majority of California or even a significant fraction lives somewhere with extreme heat. Yes, California has death valley...but no one lives there.

Someone else made the point of the number of days out of the year with extreme heat. I know about Phoenix, usually 100+ days over 100, and many days where it doesn't even drop below 100. But in areas that are hot and humid, is it a constant all summer long thing, or does it come in waves?

Spend some time in New Orleans in July, August, and Sept. It's basically continuous.
It doesn't cool of at night, even--and the humidity stays in the 90's. I went outside, the day we left there, at 3:00AM- the temperature was 96F, humidity was 93%
And for whomever said you seldom get humidity over 90% when the temperature is above 90, Houston and New Orleans would like a copy of that law...

 

[Dancing David]

I suppose what I'm wondering is that often people who tell me I shouldn't complain about the heat are someplace where it is only 90F but with a humidity level north of 50%. So I guess what I'm asking is: would you prefer 90F (32C) with 50-60% humidity to 115F (43C) with low humidity?

Dry heat is just as uncomfortable.

Dew point is the key (with humidity):
< 60 F comfortable
60-65 some are uncomfortable
65 -70 most will say yuck it is humid
70+ definitely uncomfortable

 

[Jrrarglblarg]

I suppose what I'm wondering is that often people who tell me I shouldn't complain about the heat are someplace where it is only 90F but with a humidity level north of 50%. So I guess what I'm asking is: would you prefer 90F (32C) with 50-60% humidity to 115F (43C) with low humidity?

Above 80% humidity 90f "feels like" 115f. Regardless of humidity 115f is in the realm of freakishly hot.

 

[lobosrul]

[qimg]http://www.srh.noaa.gov/images/oun/wxsafety/summerwx/heatindex.gif[/qimg]

Above 80% humidity 90f "feels like" 115f. Regardless of humidity 115f is in the realm of freakishly hot.

It looks to me like 90F at 80% feels like 105F, which I would agree with. Am I reading the chart wrong?

Edit: Or 110F, those lines are hard to follow.

 

[Dymanic]

While I understand your premise, that you'd have to control for the health of the individual, I don't think the majority of California or even a significant fraction lives somewhere with extreme heat. Yes, California has death valley...but no one lives there.

Kinda makes you wonder why anyone lives in Indio, or Las Vegas, or Phoenix, if you really think about it.

During the recent heat wave some weeks ago, Death Valley drew a large number of visitors when the word went out that there was a possibility that it would break its own record for the highest reliably reported air temperature in the world -- 134 °F (56.7 °C) -- on July 10, 1913. This suggests that among the things you'd have to control for is the mental health of the individual. And sure enough, that factor appears on a table in the article you linked.

I know about Phoenix, usually 100+ days over 100, and many days where it doesn't even drop below 100. But in areas that are hot and humid, is it a constant all summer long thing, or does it come in waves?

The innacuracy of those numbers suggests that there are some things you don't know about Phoenix. To be fair, it's been quite a while since I lived there myself, and my understanding is that weather patterns there have changed some in recent years. With that disclaimer in mind, my answer to your question -- with respect to Phoenix specifically -- is that while dry heat prevails through much of the summer (which is at least seven months long, as I recall), from somewhere around mid-July to mid-September, there's this thing called the "monsoon season" during which high temperatures are not infrequently accompanied by high humidity -- coming, yes, in waves.

 

[Belgian thought]

There can be so many explanations for that. Perhaps the more tolerable dry heat causes people to spend more time outside in dry areas, whereas in humid areas people tend to stay indoors or otherwise shield themselves?

I remember hearing somewhere that in dry heat the person is not aware of how much they are sweating since the sweat evaporates quickly. They do not see the sweat and thus do not replenish the body with water accordingly.

Whereas in humid heat, the sweating is more noticeable and thus leads to that person to drinking more fluids to compensate.

My own personal experience - Madrid 2008 - 35C noon to 14:00, humidity very low but i do not exactly remember the figure, no problem walking around.

As I type, London 2013 23:57 - 25C Humidity 60% - horrible. On the plus side - I can see my sweat so I am drinking...

 

[Giraffe107]

I'd be surprised if 1% of homes around here didn't.

Queensland has roughly 90% AC penetration (source: Queenslander Household Energy Survey 2009).

As I type, London 2013 23:57 - 25C Humidity 60% - horrible. On the plus side - I can see my sweat so I am drinking...

ha! 60% is lovely, 95% is awful. Source- it's 50-60% humid here most of the year. It's mid winter and the forecast for today is 25C, 70% humidity, it's a beautiful day.

 

[mike81]

Right now it is 80 F and 78% humidity. After spending just a few minutes outside doing yard work, my cloths are soaking wet. I much rather be in 100 degree heat in Vegas.

 

[xtifr]

OK, but the OP was talking about California. That's why I thought it important to define where we were talking about when saying most people don't have AC.

I'm pretty sure most people participating in this discussion have AC...even in their cars!

I live in Northern California, have a six figure salary, and don't have AC for my home, and almost never have (and rarely used it when I did). My house is tucked around behind several other houses, so I can see all four sides without violating anyone's property rights, and none of the five houses closest to me have any AC either. Neither do the other two units in my house. A good percentage of my friends don't bother with AC either--and the majority of the ones that do live on the other side of the coastal hills, and are isolated from the sea/bay. This is a temperate climate, which gets uncomfortably hot so rarely that many of us find little reason to bother with an air conditioner in our houses.

(Cars and office buildings are another matter.)

So seeing "California" and leaping to the conclusion AC will be the norm is somewhat unjustified, unless you specify what part of California. (La-la land is a whole 'nuther matter.)

 

[BStrong]

Purposely so. I just wanted to see if people would think past their personal comfort levels to what is actually worse.

Dry heat is worse. That's why you have deserts sand dust bowl fire etc. Dry heat kills.

Humid heat is better. That's why you have jungle Everglades Amazon bayou etc.... Humid heat brings life in over abundance.

Humidity might not be comfortable, but I'll take it any day.

Try living and working in the outdoors in Central America and get back to us.