Why do media meteorologists never refer to a Summer windchill factor? Think about it, the wind makes it seem cooler in the winter. But it also makes it seem cooler in the summer. Indeed, to avoid heat exhaustion, it would seem just as important, at least to me, to tell how much the Summer wind cools you (which it surely does, you have to agree with me). Alright, alright, maybe they can call the Summer wind-cooling factor something different if they want. But it definitely still exists. So why don’t they ever give it?
They don’t make a big noise about the humidity in winter either, do they? We always hear in wintertime about the temperature plus the wind-chill (which makes it feel colder), and in summertime about the temperature plus the humidity (which makes it feel hotter).
Because death from hypothermia is more acute at winter temperatures than summer temperatures. In addition, the chances of developing frostbite in a winter wind are substantially higher than with a summer wind.
In winter we talk about the wind chill becuase even though it’s 10 degrees outside, the wind may make it feel like an uncomfortable -30. However in summer, when it’s 85 outside, the wind feels nice, so we don’t talk about it, however, the humidity might make it feel like it’s an uncomfortable 100. (See a pattern, the news people would rather talk about things that make us uncomfortable). Anyways, this is referred to as the Heat Index. Wind Chill is the temp that the wind makes it feel like, while Heat Index is the temp that the humidity makes us feel. I don’t know you’re location, but if it’s somewhere dry, I’m guessing they don’t talk about it much. If it’s in a humid location, you’ve no doubt heard the term before. As for deaths, there’s more in winter, true (weather related anyways), but a few really hot days, and we there’s usually a a bunch of them as well. But I tend to notice that becuase our business services restautants and catering outfits, and between those and a bunch of nursing homes in the area, business tends to spike after a stretch of really cold or really hot days (due to people all meeting at restaurants or banquet halls after a funeral).
In the summer, the meteorologists (who rarely have anything to say about meteors) speak of “heat index,” which is the temperature calculated with the humidity in a way that I don’t understand.
That’s rarely a useful figure. I work with a scale of, “It’s hot, Hoo-boy it’s hot, Vinyl Car Seat Warning hot, Sweet Mercy Magruder it’s hot, and I’ll get the mail tomorrow hot.”
To paraphrase Mark Twain, I’ve been to San Francisco’s Candlestick Park (well, some call it Monster Park) and there can definitely be a wind chill factor there during the summer.
Also windchill cools by convection, which is proportional to the difference between your body temperature and the temperature of your surroundings. If it’s really cold out, say -10, that difference is over 100 degrees. If its really hot out, say 90, then its more like 8 degrees.
So the reason they ignore it in the summer is that its effect is negligible.
(I’m ignoring things like humidity and sweating here, which I imagine make the effect of wind on body temperature more complicated, as the wind will also help remove heat by speeding evaporation from the surface of your skin).
I think they should call it a “Comfort Factor” whether it’s wind chill or heat/humidity. That way it just relates to how we feel. Does anyone know what temperature the “wind chill” reporting kicks in? It seems that when you’re in the 50s, they never mention it.
AccuWeather calls it (windchill, humidity, cloud cover and whatever else factors in on a particular day) their RealFeel® temperature, and they give it summer and winter. Our local news still calls it “Heat Index”, but it’s definitely reported.
Last summer alot of Wisconsin had a “Stale Air warning” For several days (I think it was about a week), there was NO breeze, the air just didn’t move at all. It was in the 90’s I beleive and it felt like you where in an oven.
If we discount the effect of evaporation, then I think you’re right. The wind would blow away the air around you that your body has “cooled” to closer to 98.6 and replace it with the warmer 110 degree air.
But since the wind also helps your body loose heat through aiding evaporation of sweat, I think the net effect is still cooling at high temperatures, since again, even in extremely high temperatures, the temperature difference between your body and the air is rarely less the +20 on a really hot day, so convection is minimal.
Wind chill ultimately is meaningless. (See Slate for a discussion.) The numbers make all sorts of assumptions that essentially, don’t apply to anyone. Left out are things like your size, what you’re wearing, variable winds, sunlight, where you’re located, etc. It gives a phony precision to a subjective feeling, but is just cooked numbers whose utility is limited.
It’s also misleading. It doesn’t tell you how cold your skin will get, for instance. (The temperature determines that.) Your car will start exactly the same whether the wind is blowing on it or not. All it determines, at best, is how quickly things will chill down to ambient temperature. A “chill index” – set in minutes – would be much more useful.
Anyone who’s been out in -20F will tell you that it’s a hell of a lot different from a day in the that’s 20F with a wind chill of -20.
