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The dew point here in June last year approached 70F, with temperatures of 30C, and that was pretty muggy. High dew points here aren't very common either, indeed during July 2006 the dew point was rarely above 58F
Nice, I didn't think such a combo was possible in northern England, as opposed to the Southeast.
Though it's weird, here in July 2006, at their highest, the humidity levels were about the same as last June. In fact in northern France it's remembered as a "humid" heat wave, contrary to the 2003 one.
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Originally Posted by Weatherfan2
In my experience of dewpoint up to around 20°C I've not found it to be that "muggy", because probably the temperature was not much higher. Perhaps if we got 30°C and such dewpoints it would be muggy. Mind you my heat/humidity tolerance levels are better than most peoples.
I tend to notice the humidity more when the temp is significantly higher than the dewpoint. A 20°C dew point with pouring rain during a storm is certainly different from a 20°C dp with intense sunshine on a 30°C+ afternoon.
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Originally Posted by nei
The humidex never made much sense to me: if 80°F and 65°F feels like 91°F then what does 80°F truly feel like? 91°F? I've experienced a dry-ish 91°F and it feels nothing like 80°F with a dew point of 65°F.
I don't like these indexes, I prefer the temp + dew point combo over any "cooked up" formula (no offense to the inventors!). At the humidity levels I've experienced my feeling is somewhere between the humidex and the heat index, leaning towards the former. Maybe because I'm not accustomed to humidity I tend to notice it more thus feeling closer to the humidex than, say, a New Englander?
But yeah I find it quite a bit overstated.
I don't like these indexes, I prefer the temp + dew point combo over any "cooked up" formula (no offense to the inventors!). At the humidity levels I've experienced my feeling is somewhere between the humidex and the heat index, leaning towards the former. Maybe because I'm not accustomed to humidity I tend to notice it more thus feeling closer to the humidex than, say, a New Englander?
It might be because I'm used to some humidity in the summer, so when I hear feels like 30°C I imagine somewhat humid weather, a dry 30°C is not what I think of when I hear 30°C, though neither do I imagine extremely sticky (22°C + dew points) weather.
So the Canadian humidex will give the same humidex as the air temperature at 7°C. Past about 11°C, it starts going noticeably higher than the temperature. This seems odd to me. A dew point of 15°C is close to neutral for me in the summertime, maybe slightly humid but not by much. I can sense that it's not dry but the humidity isn't extremely noticeable. The American heat index will give 29.5°C for that combination. I wouldn't go so far as to say a 15°C dew point makes the air feel cooler, but close enough. Interestingly, the dew point that makes the heat index identical to air temperature decreases with increasing air temperature.
What dew points does Paris get when it's near 30°C?
Nice, I didn't think such a combo was possible in northern England, as opposed to the Southeast.
Though it's weird, here in July 2006, at their highest, the humidity levels were about the same as last June. In fact in northern France it's remembered as a "humid" heat wave, contrary to the 2003 one.
Yeah, pretty impressive I think.
Just checked 27th June 2011, maximum temperature 30.6C, dew point 20.4C
Conversely, in July 2006, at New Farnley, the maximum temperature was 32.2C with a dew point of 10.2C, and according to the Humidex, it actually felt cooler than the actual temperature. Relative humidity at the time was 26%. So it appears humid heat is rare in the UK.
It might be because I'm used to some humidity in the summer, so when I hear feels like 30°C I imagine somewhat humid weather, a dry 30°C is not what I think of when I hear 30°C, though neither do I imagine extremely sticky (22°C + dew points) weather.
It's a good point that even the phrasing of "feels like 30C" presupposes a baseline for what "a normal" 30C should feel like, which is one at low humidity. In that way, it's subjective. Some standard (probably based on what the inventor was used to?) was set as to what humidity at a given temperature should feel to the human body, "normal".
It then implies that 30C at higher humidities than that given humidity is out of the ordinary that makes it feel like "not the real temperature", but hotter and 30C at lower humidities than that also makes it feel like "not the real temperature", but cooler.
This probably favours those used to drier climates (since it seems to suppose a low humidity as the baseline), for they can expect that their 30C is what is meant and when they get into a humid climate or a muggy day, they can say, well it's 30C out now but it feels like what I expect 35C to feel like in my climate. On the flip side, if you are used to a humid climate, you can't go out to a drier climate and go out in drier air than you're used to and exclaim (well, okay you can but I never hear it) "Hey, it's 35C out today but it only feels like 30C (based on what I expect in my climate)".
A curious effect is that for those of us used to more humid climates seem to get it into our heads when we check our humidex/heat index that our summer days feel like more often than not "higher than the real temperature". It almost sounds like strange logic to have it not feel like the real temperature more often than not, at least on most summer days.
I've found the humidex much more accurately captures my sensations than the heat index, at least up to around an air temperature of 90F. Past around there the heat index seems to be more accurate for me. I just wish there was a smooth way to bridge the two scales . A crucial advantage of the humidex for me is that it registers a higher feels-like temperature in muggy weather than the heat index will at temperatures that are around 80F or below.
To me 70F with high humidity will feel much hotter than a dry 70F, and the humidex registers that feels-like increase, whereas the heat index will be about the same as the air temperature. This advantage is even more significant as temperatures go up to around 26C; hotter than that the heat index starts to kick in with feels-like increases. Even a temperature in the 60's F with a high dew point will feel hotter to me than the temperature alone indicates, and the humidex captures that very accurately for me. Although the main sensation below 20C or so is mugginess more so than heat, the extra heat is present. Below about 13C I don't notice any difference in feels-like temperature; I'm still much more comfortable with a dry 13C as opposed to a humid one, but there is no extra heat sensation.
For me any dew point above 15C is humid and perhaps muggy, with a dew point above 21C being very humid and really intolerable. My neutral level is actually closer to 10C, provided the weather is warm, and I don't perceive the air to be dry unless the dew point is significantly below 10C.
To me 70F with high humidity will feel much hotter than a dry 70F, and the humidex registers that feels-like increase, whereas the heat index will be about the same as the air temperature.
They're roughly the same to me, though I can definitely notice the humidity. If I'm moving about a lot, the humid one will make me sweat though. But I'd never refer to any 70°F temperature as humid.
Last fall, it was pouring rain and 72°F (dewpoint 70-71°F). Took a bus, and the bus had A/C which I thought was miserable. Asked the bus driver to turn off the bus, and she said "it's humid", I want to respond "so what? It's not hot". She turn it down a bit, but it still came on. I opened the window but it didn't help that much. There were a number of others who were uncomfortable, but I was the worst, as I was completely soaked since I forgot my umbrella. I actually wanted the heat on...
^^ Haha at least in western Europe one won't experience such things. Though you don't need AC to feel cold in the summer here.
Quote:
Originally Posted by nei
It might be because I'm used to some humidity in the summer, so when I hear feels like 30°C I imagine somewhat humid weather, a dry 30°C is not what I think of when I hear 30°C, though neither do I imagine extremely sticky (22°C + dew points) weather.
So the Canadian humidex will give the same humidex as the air temperature at 7°C. Past about 11°C, it starts going noticeably higher than the temperature. This seems odd to me. A dew point of 15°C is close to neutral for me in the summertime, maybe slightly humid but not by much. I can sense that it's not dry but the humidity isn't extremely noticeable. The American heat index will give 29.5°C for that combination. I wouldn't go so far as to say a 15°C dew point makes the air feel cooler, but close enough. Interestingly, the dew point that makes the heat index identical to air temperature decreases with increasing air temperature.
What dew points does Paris get when it's near 30°C?
I guess around 15°C as an average. Last year had 2 days with 20°C+ dew points and 30°C+ temps in the same time. But even then when the temp rises too much the dew point tends to decrease: History : Weather Underground
I searched for such combinations late in the evening. I found a 30°C+20°C one at midnight on August 13, 2003: History : Weather Underground
Add 2 or 3°C for Paris centre and you get uncomfortable sleeping conditions.
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Originally Posted by dunno what to put here
Yeah, pretty impressive I think.
Just checked 27th June 2011, maximum temperature 30.6C, dew point 20.4C
Yes, impressive indeed. Fortunately for you it doesn't happen too often.
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Originally Posted by Stumbler.
It's a good point that even the phrasing of "feels like 30C" presupposes a baseline for what "a normal" 30C should feel like, which is one at low humidity. In that way, it's subjective. Some standard (probably based on what the inventor was used to?) was set as to what humidity at a given temperature should feel to the human body, "normal".
It then implies that 30C at higher humidities than that given humidity is out of the ordinary that makes it feel like "not the real temperature", but hotter and 30C at lower humidities than that also makes it feel like "not the real temperature", but cooler.
Exactly my thoughts. It feels like the heat index was created for humid climates and the humidex for dry ones. I find it odd since the most populated part of Canada, the Golden Horseshoe and basically anything from Saskatchewan eastwards experiences humid heat more often than dry.
I don't like these indexes, I prefer the temp + dew point combo over any "cooked up" formula (no offense to the inventors!).
I would like to add that I agree with this - if I had to choose I'd prefer a temperature and dew point readout rather than just some index, as temp+dew is more useful to me, and I have rather intimate knowledge of how differing dew points and temperatures interact and affect my bodily comfort, which is often a bit divergent from any index.
As for the heat index and humidex's preconceptions as for "normal feelings" for different temperatures, it presupposes that a moderately dry condition is normal, and that sort of humidity level is sort of neutral for most people. That baseline was chosen I believe as the best method to use and the one that gets the point across, that humidity adds to the discomfort of heat. The effects of heat on the human body, which is what these indices try to measure, are better conveyed by presupposing a moderately dry condition as normal, that way the added humidity's effect can be more clearly seen. What works better? Saying that it's 25C and feels like 30C (presupposing a dry/moderate condition) or saying it's 25C and feels like 25C (presupposing a humid condition)? Obviously the latter is meaningless as it relates to conveying the bodily effect of higher humidity, and drier conditions than the maximum humidity don't make it "feel colder"; it's more accurate to say that "added" humidity makes it feel hotter, and an index that presupposes humidity as abnormal is better able to capture that.
I guess around 15°C as an average. Last year had 2 days with 20°C+ dew points and 30°C+ temps in the same time. But even then when the temp rises too much the dew point tends to decrease: History : Weather Underground
The record for that month was 78°F; I can't remember anything higher, might have gotten higher but it'd be unusual. Those high (anything much about 70°F) dew points don't last long; anything much about 70°F. That day you picked out was the hottest day of the year. Normally doesn't get that humid, the average for the month was 63°F and that was a few degrees above average. But our summer dew points are rather variable, more so than temperatures. Often it feels like cold fronts in summer dry the air more than cool it (at least for daytime temps).
Quote:
I searched for such combinations late in the evening. I found a 30°C+20°C one at midnight on August 13, 2003: History : Weather Underground
Add 2 or 3°C for Paris centre and you get uncomfortable sleeping conditions.
30°C at midnight? Our nights tend to cool down even if the dew point is high. Hottest I found was 79°F (26°C) at midnight. I can't imagine getting 30°C at midnight here. I wonder that happens frequently in the US south…How'd people in Paris manage without A/C? 26°C is difficult enough if your day has been very hot.
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