It’s been miserably hot here lately, (as it has been for most folks elsewhere) prompting me to ask the hive of knowledge… What criteria do “they” use, per the subject header?
IMHO the persons responsible for the index (where is it, and how can I view it?) don’t have a clue.
It was 88 degrees here today, with the relative humidity/dew point in the stratosphere…
The local TV weathercaster said “The heat index makes it feel (sic) like it’s 100 degrees”.
I beg to differ. I’ve experienced 100 degree + weather in the Western desert areas of the U.S. and in the Mediterranean, and it was actually very comfortable. The 88 degree day we had here today with the accompanying high humidity was, to put it mildly, insufferable… Much hotter to the senses than the 100 degree days that I have experienced in dryer climes.
Is there a control group for this index, who have different “feelings” that I have been left out of?
Its for someone outside doing something like hiking or playing sport or working such as labourer.
I suppose the measure is against relatively dry still air.
A dry wind will send the effective temperature …as felt by human skin … down.
If the air is very humid, then the human who is working will have to sweat more, and since that occurs to keep the body at 38 C, roughly 100F, thats the temperature you feel if its very humid.
Now when you were in 100F, what was the humidity ?
Also, they probably mean conditions in the shade, so being out in the sun is going to be hotter.
I appreciate your effort, but disagree with you that the index is intended solely for those who labour. Obviously, those who are outdoors will be affected to a greater extent than those who are in climate controlled areas.
However, apples to apples. The perception of heat (outdoors) will be the same, regardless of ones occupation, wind, shade, humidity, etc.
Of course the NWS is anti-science … are you kidding me … weather forecasting is strictly black magic … you get your willow stick your junior year at weather forecasting school … so both of you can learn these dark arts together … since when has “feels like” been a scientific term?
Just joking … very little of what the NWS does is based on magic … but Heat Index does happen to be one of them. It is controversial, and the values should be treated as very approximate. It’s handy when issuing heat watches and warnings, and these bulletins save lives … and saving lives is a mandate the NWS takes very seriously. It’s fair to say it’s there simply to make the public aware of “dangerous” weather conditions. There’s no empirical scientific basis for it.
Certainly these heat index values can be below actual temperature. Here today we had 97ºF and 14% RH … that gives 93ºF heat index … the breeze was up and I drank water all day … felted like 88ºF to me. This is why I say “I’d rather be in Redding, CA at 115ºF than Atlanta, GA at 95ºF” … that’s the God’s Truth.
Just curious, why did you sic the word “feel” … it’s spelted correctly and it is the word the NWS uses … I can’t figure out what you’re claiming is wrong within the original quote that you don’t what to be responsible for.
It is, yes, but I’ve lived my entire life in the midwest, literally a stone’s throw from Lake Michigan. Once you start getting over 85, it’s pretty bad. The handful of 100 degree days we have are almost unbearable.
The few times I’ve been down to Las Vegas, I’m always surprised when I find out how high the temperature is. My guess is usually off by 10 or so degrees. The old saying ‘it’s not the heat, it’s the humidity’ holds up pretty well.
It’s my understanding that the whole point of the heat index is to take into account the humidity. That is to say “today it’s 80, but because it’s so muggy out, it feels like it’s 90”.
We do it in winter as well, with the Wind Chill Factor. It’s 20 out, but taking the wind into account it’ll feel like 10.
I have a chart at work thay shows heat index values based on temp and humid. If its 95 in arizona, but the humidity is low (<50%?). The the 95 will actually feel like 90 ish. Compared to 95 in iowa, and 75% humidity will feel much hotter than that.
Ive always felt dew point is a better indicator of ‘mugginess’ than humidity. Apparently in places where corn grows, the dew point is 5 - 10° higher based strictly on corn releasing moisture into the air
Yeah. It’s not supposed to be quantum mechanics. It’s just a nudge technique to get people to remember that humidity counts. A helpful warning to people who have to be outdoors on a hot-humid day that they might want to take some extra precautions over just what the thermometer reads. That’s a good thing.
I’ll be the one to agree with you here. I used to laugh at the whole “it’s a dry heat” explanation when people talk about the 110+ degree weather in Phoenix, but, after experiencing it a couple summers ago, I’ll take that weather over the low 90s with humidity here in Chicago. I suffer much more in that “88 degrees with a heat index of 100” weather here than I do in actual 100 degree weather in a dry climate. Hell, I’ll take 110 over it.
The index is calculated via a certain method.
But humans do not react to, or perceive things by a set universal method.
Several people experiencing the same temperature and humidity will perceive it differently. The same person may perceive it differently at another time or situation. In your house trying to sleep or at the beach.
Not sure how it is calculated. But I would suppose there are various combinations of heat and humidity that calculate out to the same heat index. But might feel very different to a particular person. When and how much they sweat. Various metabolic things.